Mirror driving device, optical scan control apparatus, and mirror driving method

Patent metadata

Field	Value
Publication number	US-11009697-B2
Application number	US-201916366219-A
Country	US
Kind code	B2
Filing date	Mar 27, 2019
Priority date	Apr 18, 2018
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

A mirror driving device includes a detector configured to output a detection signal having a ringing component included in oscillation of a mirror, a driving waveform generator configured to generate a sawtooth driving waveform that oscillates the mirror, a superimposing waveform generator configured to generate a superimposing waveform to be superimposed to the sawtooth driving waveform, a periodic signal generator configured to generate a periodic signal having a frequency identical to or near a ringing frequency of the ringing component, a correlation calculator configured to calculate a correlation value between the periodic signal and the detection signal, and an amplitude adjuster configured to adjust an amplitude of the superimposing waveform to reduce the ringing component, based on the correlation value.

First claim

What is claimed is:

1. A mirror driving device comprising:
a detector configured to output a detection signal having a ringing component included in oscillation of a mirror;
a driving waveform generator configured to generate a sawtooth driving waveform that oscillates the mirror;
a superimposing waveform generator configured to generate a superimposing waveform;
a circuit configured to superimpose the superimposing waveform to the sawtooth driving waveform;
a periodic, signal generator configured to generate a periodic signal having a frequency identical to or near a ringing frequency of the ringing, component;
a correlation calculator configured to calculate a correlation value between the periodic signal and the detection signal; and
an amplitude adjuster configured to dynamically adjust an amplitude of the superimposing waveform to reduce the ringing component, based on the correlation value.

2. The mirror driving device as claimed in claim 1 , wherein the amplitude adjuster includes
a controller configured to perform a Proportional Integral (PI) control or a Proportional Integral Differential (PID) control that determines the amplitude based on the correlation value, and
a multiplier configured to adjust the amplitude according to an output of the controller.

3. The mirror driving device as claimed in claim 1 , wherein the detector filters a sensor signal having a waveform that varies according to the oscillation of the mirror, to output the detection signal.

4. The mirror driving device as claimed in claim 1 , wherein
the sawtooth driving waveform has a rise period in which a signal level rises, and a fall period in which the signal level falls, and
a period in which the periodic signal is output is one of the rise period and the fall period having a time width longer than the other of the rise period and the fall period.

5. An optical scan control apparatus comprising:
a mirror driving device according to claim 1 ; and
the optical scanning device including the mirror.

6. The mirror driving device as claimed in claim 1 , wherein the correlation value corresponds to an accumulated value of products of the periodic signal and the detection signal.

7. The mirror driving device as claimed in claim 6 , wherein the accumulated value includes a first correlation value between a sine wave signal forming the periodic signal and the detection signal, and a second correlation value between a cosine wave signal forming the periodic signal and the detection signal.

8. A mirror driving device comprising:
a detector configured to output a detection signal having a ringing component included in oscillation of a mirror;
a driving waveform generator configured to generate a sawtooth driving waveform that oscillates the mirror;
a superimposing waveform generator configured to generate a superimposing waveform to be superimposed to the sawtooth driving waveform;
a periodic signal generator configured to generate a periodic signal having a frequency identical to or near a ringing frequency of the ringing component;
a correlation calculator configured to calculate a correlation value between the periodic signal and the detection signal; and
an amplitude adjuster configured to adjust an amplitude of the superimposing waveform to reduce the ringing component, based on the correlation value,
wherein the correlation value corresponds to an accumulated value of products of the periodic signal and the detection signal.

9. The mirror driving device as claimed in claim 8 , wherein the accumulated value includes a first correlation value between a sine wave signal forming the periodic signal and the detection signal, and a second correlation value between a cosine wave signal forming the periodic signal and the detection signal.

10. The mirror driving device as claimed in claim 8 , wherein the amplitude adjuster includes
a controller configured to perform a Proportional Integral (PI) control or a Proportional Integral Differential (PID) control that determines the amplitude based on the correlation value, and
a multiplier configured to adjust the amplitude according to an output of the controller.

11. The mirror driving device as claimed in claim 8 , wherein the detector filters a sensor signal having a waveform that varies according to the oscillation of the mirror, to output the detection signal.

12. The mirror driving device as claimed in claim 8 , wherein
the sawtooth driving waveform has a rise period in which a signal level rises, and a fall period in which the signal level falls, and
a period in which the periodic signal is output is one of the rise period and the fall period having a time width longer than the other of the rise period and the fall period.

13. An optical scan control apparatus comprising:
a mirror driving device according to claim 8 ; and
the optical scanning device including the mirror.

14. A mirror driving device comprising:
a detector configured to output a detection signal having a ringing component included in oscillation of a mirror;
a driving waveform generator configured to generate a sawtooth driving waveform that oscillates the mirror;
a superimposing waveform generator configured to generate a superimposing waveform to be superimposed to the sawtooth driving waveform;
a periodic signal generator configured to generate a periodic signal having a frequency identical to or near a ringing frequency of the ringing component;
a correlation calculator configured to calculate a correlation value between the periodic signal and the detection signal; and
an amplitude adjuster configured to adjust an amplitude of the superimposing waveform to reduce the ringing component, based on the correlation value, wherein
the sawtooth driving waveform has a rise period in which a signal level rises, and a fall period in which the signal level falls, and
a period in which the superimposing waveform is superimposed to the sawtooth driving waveform is one of the rise period and the fall period having a time width shorter than the other of the rise period and the fall period.

15. The mirror driving device as claimed in claim 14 , wherein the amplitude adjuster includes
a controller configured to perform a Proportional Integral (PI) control or a Proportional Integral Differential (PID) control that determines the amplitude based on the correlation value, and
a multiplier configured to adjust the amplitude according to an output of controller.

16. The mirror driving device as claimed in claim 14 , wherein the detector filters a sensor signal having a waveform that varies according to the oscillation of the mirror, to output the detection signal.

17. The mirror driving device as claimed in claim 14 , wherein
the sawtooth driving waveform has a rise period in which a signal level rises, and a fall period in which the signal level falls, and
a period in which the periodic signal is output is one of the rise period and the fall period having a time width longer than the other of the rise period and the fall period.

18. An optical scan control apparatus comprising:
a mirror driving device according to claim 14 ; and
the optical scanning device including the mirror.

19. A mirror driving method comprising:
computing a correlation value between a detection signal having a ringing component included in oscillation of a mirror, and a periodic signal having a frequency identical to Or near a ringing frequency of the ringing component;
superimposing a superimposing waveform to a sawtooth driving wavefor

Assignees

• Hayashi Yugo
• Mitsumi Electric Co Ltd

Inventors

• Hayashi Yugo

Classifications

• G02B26/105 Primary

  with one or more pivoting mirrors or galvano-mirrors (G02B26/101 takes precedence) · CPC title

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title

• G02B26/0858

  the reflecting means being moved or deformed by piezoelectric means · CPC title

• G02B26/127

  Adaptive control of the scanning light beam, e.g. using the feedback from one or more detectors (G02B27/0031 takes precedence) · CPC title

• H02N2/0075

  Electrical details, e.g. drive or control circuits or methods · CPC title