JP4285725B2 - Optical scanning device - Google Patents

Optical scanning device Download PDF

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Publication number
JP4285725B2
JP4285725B2 JP2002195527A JP2002195527A JP4285725B2 JP 4285725 B2 JP4285725 B2 JP 4285725B2 JP 2002195527 A JP2002195527 A JP 2002195527A JP 2002195527 A JP2002195527 A JP 2002195527A JP 4285725 B2 JP4285725 B2 JP 4285725B2
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Japan
Prior art keywords
mirror
rotation axis
optical scanning
scanning device
substrate
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
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JP2002195527A
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Japanese (ja)
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JP2004037886A (en
Inventor
幸人 佐藤
光美 藤井
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株式会社リコー
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Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a micro optical system to which a micromachining technique is applied, and more particularly to an optical scanning device that reciprocally vibrates a micro mirror about a torsion beam as a rotation axis.
[0002]
[Prior art]
In the optical scanning device described in IBM J.Res.Develop Vol.24 (1980), a mirror supported by two beams provided on the same straight line is connected to an electrode provided at a position facing it. The two beams are reciprocally oscillated around the torsional rotation axis by the electrostatic attractive force between them. This optical scanning device formed by micromachining technology has a simple structure and can be formed in a batch in a semiconductor process compared to a conventional optical scanning device using a polygon mirror rotation using a motor. Easy, low manufacturing cost, and single mirror surface, so there is no effect of variations in the accuracy of multiple mirror surfaces such as polygon mirrors. Furthermore, because it is reciprocating scanning, it can handle high speed. There is.
[0003]
With regard to such an electrostatically driven torsional vibration type optical scanning device, Japanese Patent No. 2924200 describes that a beam is formed into an S-shape to reduce the rigidity so that a large deflection angle can be obtained with a small driving force. ing. Japanese Patent Application Laid-Open No. 7-92409 discloses a beam whose thickness is made thinner than that of a mirror or a frame. Japanese Patent No. 3011144 or The 13th Annual International Workshop on MEMS2000 (2000) 473-478 describes a case where the fixed electrode is arranged at a position not overlapping the vibration direction of the mirror portion. In the 13th Annual International Workshop on MEMS2000 (2000) 645-650, the counter electrode is installed at an inclination from the center position of the mirror deflection, and the drive voltage is lowered without changing the mirror deflection angle. Is described. Japanese Patent Laid-Open No. 2001-249300 discloses a mirror structure that reduces the weight of the mirror part and is less likely to warp, and has a plurality of recesses (thickening parts) formed on the back surface of the mirror part. A relatively small size is described as the distance increases (FIG. 6 of the same publication). Regarding the sealing and electrical connection of the vibration space, for example, Japanese Patent No. 2924200 describes a typical structure by hermetic sealing and wire bonding (FIG. 7 of the same publication).
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above prior art, and in an optical scanning device configured to reciprocally vibrate a mirror using a torsion beam as a torsion rotation axis, the mirror is reduced in weight and the occurrence of warpage is effectively suppressed. The main object is to enable more stable optical scanning.
[0005]
[Means for Solving the Problems]
The basic principle of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic perspective view for explaining the basic structure of an optical scanning device according to the present invention. Reference numeral 31 denotes a mirror substrate . For example, a mirror 33, a pair of twisted beams 32 and a frame 34 are integrally formed from a silicon substrate having a relatively high impurity concentration by a semiconductor process technique such as photoetching. The mirror 33 can reciprocate with the torsion beam 32 as a torsion rotation axis. On one surface of the mirror 33 , a mirror surface made of a metal thin film having a sufficient reflectance with respect to the wavelength of the scanning light is formed. In the middle of the assembly process of the optical scanning device, a separation groove 37 is formed in the frame 34, whereby the frame 34 is divided into four portions 39 and 40 that are electrically insulated. This is because the frame portion 39 facing the free end that is not coupled to the torsion beam 32 of the mirror 33 is used as a fixed electrode for driving. Therefore, when the fixed electrode is separately formed with a metal thin film or the like, the separation groove 37 is not necessarily formed.
[0006]
FIG. 2 is a schematic diagram for explaining the driving principle of the mirror 33. The two end portions 38 of the mirror 33 that are not coupled to the torsion beam 32 and the frame portion 39 that faces the end portion 38 with a narrow gap therebetween serve as a movable electrode and a fixed electrode, respectively. When a drive pulse as shown in FIG. 3B is applied between these electrodes by the drive pulse generator 29, an electrostatic torque Trq acts between the electrodes, and the mirror 33 reciprocally vibrates using the torsion beam 32 as a torsion rotation axis. To do. 3 (a) is a vibration waveform of the mirror 33. In order to increase the deflection angle θ (vibration amplitude) of the mirror 33, the frequency of the drive pulse is set to be the same as the resonance frequency fo determined by the moment of inertia I of the mirror 33 and the torsion spring constant Kθ of the torsion beam 32. At this time, the resonance frequency fo and the swing angle θ of the mirror 33 are given by the following equations.
[0007]
fo = (1 / 2π) √ (Kθ / I) (1)
θ = (Trq / I) * K (fo, C) (2)
However, K (fo, C) is a function of the resonance frequency fo and the viscous resistance C, and is inversely proportional to fo, C. C is the viscous resistance coefficient of the space in which the mirror vibrates.
[0008]
Due to the inertial force acting on the mirror 33 when the mirror vibrates, the mirror 33 warps as schematically shown in FIG. Since the present invention intends to effectively suppress the warp of the mirror 33, the warp of the mirror 33 will be analyzed next. 5 and 6 are explanatory diagrams thereof.
[0009]
If the acceleration acting when the mirror 33 vibrates is α, the inertial force fj acting on the minute element mj of the mirror 33 is given by the following equation.
fj = mj * αj (3)
mj: microelement mass of the mirror.
[0010]
At this time, the bending moment M that bends and deforms the minute element mj of the mirror is given by the sum from the tip of the mirror to j.
M = Σ Mj = Σfj * lj (4)
lj: the distance from the twist rotation axis of the minute element mj
The bending strength with respect to the bending moment is given by the sectional second moment I.
I = b * h ^ 3/12 (5)
h and b are the thickness and width of the mirror (see FIG. 6).
[0012]
The warpage amount δ of the mirror 33 is expressed by the following equation.
δ∝M / (E * I) (6)
E: Young's modulus of mirror 33
Here, in the mirror structure disclosed in Japanese Patent Laid-Open No. 2001-249300 (see FIG. 6 of the same publication), the minute element mass mj becomes relatively larger as it moves away from the torsional rotation axis. As can be seen from the above, the bending moment M also increases, so that the warpage amount δ increases as is apparent from the equation (6).
[0014]
On the other hand, in the present invention, as the cross-sectional secondary moment I (bending strength) in the direction parallel to the torsional rotation axis (torsion beam 32) of the mirror 33 moves away from the torsional rotation axis as shown in FIG. 7, for example. The cross-sectional shape of the mirror 33 is changed in accordance with the distance from the twist rotation axis so as to decrease . That is, the substantial thickness h and / or the substantial X-axis direction width b of the mirror 33 is reduced as the distance from the torsional rotation axis increases. By providing the mirror 33 with such a cross-sectional shape, the minute element mass mj decreases as the distance from the torsional rotation axis decreases, and thus the bending moment M also decreases. Therefore, the second-order moment of the mirror 33 as the distance from the torsional rotation axis decreases. 4 can be reduced, for example, as shown by a curve L2 in FIG. 4 (curve L1 in FIG. 4 is the amount of warpage when the moment of inertia is uniform). Thus, according to the present invention, the amount of warpage can be reduced while reducing the weight of the mirror 33.
[0015]
Specifically, the present invention provides an optical scanning device configured such that a mirror is supported by a torsion beam and the mirror is reciprocally oscillated using the torsion beam as a torsion rotation axis, and a cross section 2 parallel to the torsion rotation axis of the mirror. A plurality of thinned portions having the same area are formed on a surface opposite to the mirror surface of the mirror so that the next moment decreases as the distance from the twisted rotational shaft increases. It is characterized by increasing with increasing distance.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. Note that, in the plurality of drawings referred to in the description, the same reference numerals indicate the same or equivalent parts.
[0024]
Example 1 FIG. 8 is a perspective view for explaining Example 1 of the present invention. FIG. 9 is a schematic cross-sectional view showing a cross-sectional shape of the mirror substrate 31 taken along a cutting line parallel to the Y axis. FIG. 10 is a diagram schematically showing a cross-sectional shape of the mirror 33 cut along a cutting line parallel to the X axis (twist rotation axis). The present embodiment shows a configuration example of the invention of claim 1.
[0025]
In this embodiment, as seen in FIG. 8, a rectangular hollow portion (concave portion) 44 having the same area and the same depth is formed on the surface of the mirror 33 opposite to the mirror surface (the upper surface in FIG. 8). A plurality are formed. These thinning portions 44 are arranged so that the number increases as the distance from the twist rotation axis (X axis) increases. That is, it is configured such that the lightening area of the mirror 33 increases as the distance from the twist rotation axis increases. If FIG. 10 is referred, the area of the thick part 45 of the mirror 33 will reduce as it leaves | separates from a twist rotating shaft. Therefore, the cross-sectional secondary moment parallel to the torsional rotation axis decreases stepwise as shown in FIG. 11 as the distance from the torsional rotation axis increases. Other than this, the configuration is the same as that described with reference to FIG.
[0026]
Example 2 FIG. 12 is a perspective view for explaining Example 2 of the present invention. FIG. 13 is a schematic cross-sectional view showing a cross-sectional shape of the mirror substrate 31 cut along a cutting line parallel to the Y axis. FIG. 14 is a diagram schematically showing a cross-sectional shape of the mirror 33 cut along a cutting line parallel to the X axis (twist rotation axis).
[0027]
In this embodiment, as shown in FIG. 12 and FIG. 13, a thinned portion 50 is formed over the entire surface on the surface opposite to the mirror surface of the mirror 33 (upper surface in FIG. 12). The depth of the punched portion 50 increases as the distance from the twist rotation axis increases. That is, the thickness of the mirror 33 decreases as the distance from the twist rotation axis increases. Therefore, the cross-sectional secondary moment parallel to the torsional rotation axis decreases as shown in FIG. 15 as the distance from the torsional rotation axis increases. Other than this, the configuration is the same as that described with reference to FIG.
[0028]
<< Example 3 >> FIG. 16: is a partially broken top view for demonstrating Example 3 of this invention. However, the frame portion of the mirror substrate 31 is not shown. FIG. 17 is a schematic cross-sectional view showing a cross-sectional shape of the mirror 33 cut along a cutting line parallel to the twisting rotation axis (X axis).
[0029]
In this embodiment, as shown in FIGS. 16 and 17, a lightening portion 55 having the same depth is formed over substantially the entire surface opposite to the mirror surface of the mirror 33, but the beam 59 in the X-axis direction and The beam 60 in the Y-axis direction is left. Looking at each half of the mirror 33 across the torsional rotation axis, the beams 59 in the X-axis direction are arranged at equal intervals, but the beam 60 in the Y-axis direction increases with distance from the torsional rotation axis (number of beams). Decrease). It is the beam 60 in the Y-axis direction that contributes to the cross-sectional secondary moment, and the beam 59 has a width of several tens of μm, so it hardly contributes to the cross-sectional secondary moment. Therefore, the cross-sectional secondary moment parallel to the torsional rotation axis decreases stepwise as shown in FIG. 18 as the distance from the torsional rotation axis increases. Other than this, the configuration is the same as that described with reference to FIG.
[0030]
Example 4 FIG. 19 is an exploded perspective view for explaining Example 4 of the present invention. The optical scanning device of this embodiment is formed by bonding the base substrate 100 to the back side of the mirror substrate 31, and a cross-sectional structure in a bonded state is shown in FIG.
[0031]
In the mirror substrate 31 in this embodiment, the second moment in section parallel to the torsional rotation axis of the mirror 33 is reduced as the distance from the torsional rotation axis decreases. Yes. However, the back surface of the mirror 33 may be thinned in the same manner as in the first or second embodiment, and such an aspect is also included in the present invention.
[0032]
The base substrate 100 is made of an insulating substrate member such as Pyrex glass. A recess for securing a vibration space of the mirror 33 is formed on the back surface of the base substrate 100, and a pair of deflection angle detection electrodes 102 facing the mirror 33 is formed on the bottom surface of the recess. Further, a pair of through electrodes 104 that penetrates the front and back of the base substrate 100 and are electrically connected to the deflection angle detection electrode 102, and a pair of through electrodes 106 that are electrically connected to the frame portion 39 of the mirror substrate 31. Then, a pair of through electrodes 108 for electrical connection with the frame portion 40 of the mirror substrate 31 is formed. The deflection angle detection electrode 102 is made of, for example, a two-layer thin film in which Cr and Au are vapor-deposited. The through electrodes 104, 106, 108 are formed by filling the inside of the through hole with, for example, Ni plating after the through hole is processed. Such a through electrode also has good sealing properties.
[0033]
Such a base substrate 100 is bonded to the mirror substrate 31 as shown in FIG. After joining, the dividing groove 37 is formed in the mirror substrate 31. The frame part 39 (part acting as a fixed electrode) divided by the dividing groove 37 and the through electrode 106 are electrically connected, and the other frame part 40 and the through electrode 108 are electrically connected. Therefore, a driving pulse can be applied to the through electrodes 106 and 108 from the outside. In this way, the electrical connection for applying the drive pulse by the through electrode is generally lower in cost than the connection method by wire bonding as shown in Japanese Patent No. 2924200, and the connection The certainty is also excellent.
[0034]
In addition, since the electrostatic capacitance between the angular deflection angle detection electrode 102 and the mirror 33 changes depending on the interval between them, the deflection angle of the mirror 33 is detected by measuring the electrostatic capacitance through the through electrode 104. Can do. By controlling the drive pulse voltage in accordance with the detected deflection angle, fluctuations in the deflection angle of the mirror 33 due to disturbance can be corrected.
[0035]
<< Example 5 >> FIG. 21: is a disassembled perspective view for demonstrating Example 5 of this invention. In the optical scanning device of this embodiment, the base substrate 100 is bonded to the back surface side of the mirror substrate 31, and the cover substrate 200 is bonded to the mirror surface side of the mirror substrate 31, and the vibration space of the mirror 33 is sealed in a reduced pressure state. FIG. 22 shows a cross-sectional structure in a joined state. A hermetic seal method is used as the sealing method.
[0036]
The mirror substrate 31 is the same as that of the fourth embodiment, but may be the same as that of the first, second or third embodiment, and such an embodiment is also included in the present invention.
[0037]
The base substrate 100 is the same as that of the fourth embodiment.
[0038]
The cover substrate 200 is made of an insulating transparent member such as Pyrex glass, and a concave portion 202 for securing a vibration space of the mirror 33 is formed on the inner surface side thereof. The scanning light enters the mirror surface of the mirror substrate 33 through the cover substrate 200, and the deflected light is emitted to the outside through the cover substrate 200.
[0039]
In the optical scanning device of the present embodiment, the vibration space 204 of the mirror 33 is sealed, and entry of foreign matters such as dust from the outside is prevented, so that abnormal operations such as discharge due to foreign matter entry are less likely to occur. In addition, by reducing the vibration space of the mirror 33, the viscous resistance is reduced, and the mirror 33 can be vibrated with a large swing angle with a low driving voltage. The vibration space 204 of the mirror 33 is depressurized to atmospheric pressure or less, and the pressure is selected in the range of 0.1 (Torr) or more and 2 (Torr) or less.
[0040]
The sealing structure of the optical scanning device of the present embodiment can be reliably sealed at a lower cost than the sealing structure as disclosed in Japanese Patent No. 2924200.
[0041]
<< Substrate Bonding Method >> The substrates of the optical scanning device of Example 5 can be bonded by, for example, an anodic bonding method using an anode device as schematically shown in FIG.
[0042]
In FIG. 23, 351 is a weight for controlling the junction weight, and 352 is a power source for controlling the junction voltage. Reference numeral 353 denotes a heater, and the junction temperature is adjusted by controlling the current flowing through the heater 353 by the temperature controller 354. Reference numeral 355 denotes a vacuum pump, which keeps the inside of the apparatus at a negative pressure. Reference numeral 356 denotes an observation window.
[0043]
The joining process will be described. First, a stack of the mirror substrate 33 and the cover substrate 200 is set as a workpiece W on the anode device and joined. In this manner, the dividing groove 37 of the mirror substrate 31 is processed while being bonded to the cover substrate 200.
[0044]
Next, the mirror substrate 31 bonded to the cover substrate 200 is overlapped with the base substrate 100 and set to the anode device as a work W. For example, the load is 50 gf / cm ^ 2, the internal pressure is 0.1 Torr to 2 Torr, Bonding is performed under the bonding conditions of a temperature of 500 ° C. and a bonding voltage of 500 V × 25 minutes. As a result, the three substrates are joined, and the vibration space of the mirror 33 is sealed under reduced pressure to 0.1 to 2 torr. At the same time, the through electrodes 106 and 108 of the base substrate 100 are electrically connected to the corresponding portions of the mirror substrate 31. The
[0045]
Since Pyrex glass has good bondability by anodic bonding with silicon, if the mirror substrate 31 is formed of a silicon substrate and the base substrate 100 and the cover substrate 200 are formed of Pyrex glass, the substrates are bonded to each other. This is advantageous in that stable sealing can be achieved for a long time. However, in general, the mirror substrate 31 can be formed from any conductive material, the base substrate 100 can be formed from any insulating material, and the cover substrate 200 can be formed from any insulating and transparent material. In addition, it is natural that the mirror substrate and the base substrate in the fourth embodiment can be similarly joined by the anode connection method.
[0046]
<< Vibration Space Pressure >> Using the optical scanning device according to any one of Examples 1 to 4 (without the cover substrate 200), the following experiment was performed. In the experiment, an evaluation apparatus as shown in FIG. 24 was used. In FIG. 24, reference numeral 400 denotes a decompression container, in which the optical scanning device 402 to be evaluated is set. The laser surface of the mirror of the optical scanning device 402 is irradiated with a laser beam from the laser light source 404, and the laser beam deflected by the mirror surface is received by the optical position detector 406. The detection signal of the optical position detector 406 is input to the waveform observation device 408.
[0047]
First, the internal pressure of the decompression vessel 400 is changed in various ways, the mirror of the optical scanning device 402 is driven, the waveform of the detection signal of the optical position detector 406 (the vibration waveform of the mirror) is observed by the waveform observation device 408, and the pressure And the mirror deflection angle θ (corresponding to the amplitude of the vibration waveform). When the results were plotted, a characteristic curve as shown in FIG. 25 was obtained. As can be seen from this characteristic curve, there is a pressure Po that maximizes the deflection angle θ. Therefore, a large deflection angle can be obtained with a low drive voltage by setting the pressure in the mirror vibration space to be in the vicinity of Po.
[0048]
In order to investigate the cause of the relationship between the pressure and the deflection angle, the relationship between the pressure and the viscous resistance coefficient and the relationship between the pressure and the driving pulse / mirror vibration waveform phase difference were examined as follows.
[0049]
The internal pressure of the decompression vessel 400 is changed in various ways, the mirror of the optical scanning device 402 is driven, and the damped oscillation waveform (see FIG. 26) of the mirror from the point of time when the driving is stopped is observed by the waveform observation device 408. The viscous resistance coefficient C at each pressure was determined from the vibration waveform. When the viscous resistance coefficient C is plotted, a characteristic curve Lc as shown in FIG. 27 is obtained.
[0050]
The internal pressure of the decompression vessel 400 is changed variously, the mirror of the optical scanning device 402 is continuously driven, the mirror vibration waveform and the drive pulse waveform are observed by the waveform observation device 408, and the drive pulse waveform and mirror at each pressure are observed. A phase difference Δθ with respect to the vibration waveform was obtained (see FIG. 28). When the obtained phase difference Δθ is plotted, a characteristic curve Lθ as shown in FIG. 27 is obtained.
[0051]
From the above experiment,
(1) In the region where the pressure is lower than Po, the viscous resistance coefficient C is substantially constant, but the phase difference Δθ between the drive pulse and the mirror vibration waveform increases as the pressure decreases. For this reason, the deflection angle is considered to be small.
(2) In the region where the pressure is higher than Po, the phase difference Δθ is substantially constant regardless of the pressure, but the viscous resistance coefficient C increases in proportion to the pressure. Accordingly, the deflection angle θ decreases as the pressure increases.
[0052]
From this, it is understood that the relationship between the pressure and the deflection angle as shown in FIG. 25 occurs. If the pressure in the mirror vibration space is set to Po, the maximum deflection angle can be obtained with a low drive voltage. The optimum pressure in the mirror vibration space actually set depends on the resonance frequency determined by the moment of inertia of the mirror and the torsion spring constant of the torsion beam, but generally ranges from 0.1 (Torr) to 2 (Torr). Suitable.
[0053]
【The invention's effect】
According to the optical scanning device of the present invention, the weight of the mirror can be reduced and the occurrence of warpage can be effectively suppressed, thereby enabling more stable optical scanning.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view for explaining a basic structure of an optical scanning device of the present invention.
FIG. 2 is a schematic diagram for explaining a driving principle of a mirror.
FIG. 3 is a waveform diagram showing a mirror drive pulse waveform and a mirror vibration waveform.
FIG. 4 is a diagram showing the amount of mirror warpage and its suppression effect.
FIG. 5 is a schematic diagram for explaining a bending moment and a sectional secondary moment.
FIG. 6 is a schematic diagram for explaining a cross-sectional shape of a mirror.
FIG. 7 is a graph showing a typical relationship between a second moment of inertia of a mirror and a distance from a twist rotation axis in the optical scanning device of the present invention.
FIG. 8 is a schematic perspective view for explaining Example 1 of the present invention.
9 is a cross-sectional view of the mirror substrate of FIG. 8 cut along a cutting line orthogonal to the twist rotation axis.
10 is a schematic diagram showing a cross-sectional shape cut along a cutting line parallel to the twist rotation axis of the mirror of FIG.
11 is a graph showing the relationship between the sectional moment of inertia of the mirror of FIG. 8 and the distance from the torsional rotation axis.
FIG. 12 is a schematic perspective view for explaining Example 2 of the present invention.
13 is a cross-sectional view of the mirror substrate of FIG. 12 cut along a cutting line perpendicular to the twist rotation axis.
14 is a schematic diagram showing a cross-sectional shape cut along a cutting line parallel to the twist rotation axis of the mirror of FIG.
15 is a graph showing the relationship between the moment of inertia of the cross section of the mirror of FIG. 12 and the distance from the torsional rotation axis.
FIG. 16 is a partially broken plan view for explaining Example 3 of the invention.
17 is a cross-sectional view taken along a cutting line parallel to the torsional rotation axis of the mirror of FIG.
18 is a graph showing the relationship between the moment of inertia of the cross section of the mirror of FIG. 16 and the distance from the torsional rotation axis.
FIG. 19 is an exploded perspective view for explaining Example 4 of the present invention.
FIG. 20 is a cross-sectional view for explaining Example 4;
FIG. 21 is an exploded perspective view for explaining Example 5 of the invention.
22 is a cross-sectional view for explaining Example 5. FIG.
FIG. 23 is a schematic configuration diagram of an anode device.
FIG. 24 is a configuration diagram of an evaluation apparatus for an experiment related to a pressure in a mirror vibration space.
FIG. 25 is a graph showing the relationship between the pressure in the mirror vibration space and the deflection angle of the mirror.
FIG. 26 is a waveform diagram showing a damped oscillation waveform of a mirror.
FIG. 27 is a graph showing the relationship between the vibration waveform of the mirror, the phase difference of the drive pulse, and the mirror vibration space pressure of the viscous resistance coefficient.
FIG. 28 is a waveform diagram showing mirror drive pulses and vibration waveforms.
[Explanation of symbols]
31 mirror substrate 32 twisted beam 33 mirror 44 thinned portion 50 thinned portion 55 thinned portion 59 beam 60 beam 100 base substrate 102 deflection angle detection electrode 104 through electrode 106 through electrode 108 through electrode 200 cover substrate

Claims (1)

  1. In the optical scanning device having a configuration in which a mirror is supported by a torsion beam and the mirror is reciprocally oscillated with the torsion beam as a torsion rotation axis,
    So that the moment of inertia of the cross section of the mirror parallel to the torsional rotation axis decreases as the distance from the torsional rotation axis increases.
    An optical scanning device , wherein a plurality of thinning portions having the same area are formed on a surface opposite to the mirror surface of the mirror, and the number of the thinning portions is increased as the distance from the twist rotation axis increases.
JP2002195527A 2002-07-04 2002-07-04 Optical scanning device Expired - Fee Related JP4285725B2 (en)

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Publication number Priority date Publication date Assignee Title
US7282775B2 (en) 2004-02-13 2007-10-16 Advanced Numicro Systems, Inc. MEMS scanning mirror with trenched surface and tapered comb teeth for reducing intertia and deformation
US7046421B1 (en) 2004-02-13 2006-05-16 Advanced Nano Systems, Inc. MEMS scanning mirror with trenched surface and I-beam like cross-section for reducing inertia and deformation
US7187100B2 (en) 2004-04-20 2007-03-06 Advanced Numicro Systems, Inc. Dimensions for a MEMS scanning mirror with ribs and tapered comb teeth
JP4835024B2 (en) * 2005-04-13 2011-12-14 ソニー株式会社 Light control element, manufacturing method thereof, and display device
JP2007078819A (en) * 2005-09-12 2007-03-29 Fujifilm Corp Optical scanner element
JP5521359B2 (en) 2008-03-13 2014-06-11 セイコーエプソン株式会社 Optical deflector and manufacturing method thereof
JP5195028B2 (en) 2008-05-28 2013-05-08 富士通株式会社 Microelectromechanical element and microelectromechanical element array
JP5267370B2 (en) 2009-07-23 2013-08-21 ブラザー工業株式会社 Optical scanner
JP4958195B2 (en) * 2011-07-15 2012-06-20 パイオニア株式会社 Drive device
JP4958197B2 (en) * 2011-07-15 2012-06-20 パイオニア株式会社 Drive device
JP5906640B2 (en) * 2011-09-29 2016-04-20 セイコーエプソン株式会社 Wavelength variable interference filter, optical filter device, optical module, and electronic apparatus
JP6180155B2 (en) * 2013-04-01 2017-08-16 富士電機株式会社 Actuator

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