JP2009258645A - Two-dimensional optical beam deflector and image display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-dimensional optical beam deflector in which scanning speed is adjustable according to the frame rate per image and which beam deflector has an antishock characteristic, and to provide an image display using the optical beam deflector. <P>SOLUTION: The two-dimensional optical beam deflector 100 includes a deflection element 10 which contains resin and deflects light L in one direction and a deflection element 50 which contains Si and deflects light L in other direction. The deflection element 10 includes a pair of terminal sections 13, 14 disposed to face each other, a deflecting section 11 disposed therebetween, and beam sections 16, 17 for connecting them. The deflection element 50 includes: a frame-like support section 52; a deflecting section 53 which is arranged within the frame and has a mirror section 63; arms 54, 55 and 56, 57 which are disposed on its both sides and have each one end connected to the support section 52; beam sections 58, 59 and 60, 61 for connecting the other ends of the arms 54, 55 and 56, 57 to the deflecting section 11. The deflecting sections 11, 53 each have the center of gravity located on the optical path of light L. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a two-dimensional optical deflector and an image display apparatus using the same, and more particularly to a two-dimensional optical deflector for displaying an image by a raster scan method and an image display apparatus using the same.

  Studies are being actively conducted on the use of optical deflectors fabricated by MEMS (Micro Electro Mechanical Systems) technology for image display devices such as front projectors, rear projectors, and HMDs (Head Mount Displays).

For example, Patent Document 1 discloses a one-dimensional optical deflector made of a soft resin such as polyimide or silicone resin and capable of deflecting light in one direction, and an image display device using the same.
The image display device disclosed in Patent Document 1 uses two one-dimensional light deflectors, scans the laser light emitted from the light source in the horizontal direction with one one-dimensional light deflector, and the other The one-dimensional optical deflector scans in the vertical direction to display an image by a raster scan method.

However, in the optical deflector disclosed in Patent Document 1 and the image display apparatus using the same, it is difficult to scan the laser beam at high speed because the resonance frequency of the soft resin is as low as several tens of Hz.
When the scanning speed of the laser beam is slow, the resolution of the displayed image is low, and thus a high resolution image cannot be displayed. Therefore, further improvement in scanning speed is desired.

Further, in the optical deflector disclosed in Patent Document 1 and the image display device using the same, the optical deflector can only deflect light in only one direction, so that a two-dimensional image is displayed. Requires two optical deflectors.
For this reason, since the optical system becomes complicated, it is difficult to reduce the size of the image display device, and the product cost is increased, and improvement thereof is desired.

  In view of the above problem, Patent Document 2 discloses a two-dimensional optical deflector made of Si (silicon) and capable of optically deflecting in the horizontal direction and the vertical direction, respectively, and an image display device using the same.

According to the optical deflector disclosed in Patent Document 2 and the image display apparatus using the same, since the resonance frequency of Si is as high as several tens of KHz, the laser beam can be scanned at high speed, so that a high-resolution image can be obtained. Can be displayed.
In addition, since each optical deflection in the horizontal direction and the vertical direction can be performed at one time by one optical deflector, the image display device can be miniaturized.

JP 2006-276653 A JP 2004-110005 A

By the way, when displaying an image by the raster scanning method, as described above, the higher the scanning speed in the horizontal direction, the more scanning lines in one frame, so that a high-resolution image can be obtained, but the scanning speed in the vertical direction is The number of frames per unit time (one second) is determined according to a so-called frame rate.
Therefore, generally, the scanning speed in the vertical direction is lower than the scanning speed in the horizontal direction, and the scanning speed in the horizontal direction changes according to individual differences of optical deflectors and environmental temperature changes. However, in order to realize a certain number of scanning lines within one frame, it is desirable that the scanning speed in the vertical direction can be adjusted according to the frame rate.

  However, the optical deflector disclosed in Patent Document 2 and an image display apparatus using the same use an optical deflector having a high resonance frequency for low-speed vertical scanning. Since the device can be driven only within a narrow range of the resonance frequency of Si or in the vicinity thereof, it is difficult to adjust the scanning speed in the vertical direction according to the frame rate, and improvement thereof is desired.

  Further, in the optical deflector disclosed in Patent Document 2 and an image display apparatus using the same, a high resolution image can be displayed by one two-dimensional optical deflector, but an Si substrate which is an expensive material And the use area of the Si substrate is increased as compared with the one-dimensional optical deflecting element, so that the material cost is increased and the improvement thereof is desired.

  Further, since Si is fragile compared to a soft resin, an optical deflector made of Si and an image display device using the same may be easily damaged when an impact is applied from the outside. Improvement is desired.

  Therefore, the problem to be solved by the present invention is that a high-resolution image is obtained, the vertical scanning speed can be adjusted according to the frame rate, and a shock-resistant two-dimensional optical deflector and the same are used. Another object of the present invention is to provide an image display apparatus.

In order to solve the above problems, the present invention provides the following two-dimensional optical deflector and an image display device using the same.
1) A two-dimensional optical deflector comprising a first optical deflecting element (10) that includes resin and deflects light (L) irradiated from the outside in one direction, and Si (silicon); A second optical deflecting element (50) that deflects in another direction different from the one direction, and the first optical deflecting element is a pair of terminal portions (13, 14) that are opposed to each other and spaced from each other. ), A first deflection portion (11) disposed between the pair of terminal portions, and a pair of first beam portions (16, 16) respectively connecting the first deflection portion and the pair of terminal portions. 17), and the second light deflection element includes a frame-like support portion (52) fixed on the first deflection portion, and the first deflection within the frame of the support portion. A second deflection section (53) having a mirror section (63) that is disposed apart from the first section and reflects the light, and both the second deflection section. A pair of first arm portions (54, 55) each having one end connected to the support portion, and opposite to the first arm portion on both sides of the second deflection portion, A pair of second arm portions (56, 57) each having one end connected to the support portion, and a pair of second arms respectively connecting the other end of the first arm portion and the second deflection portion. The beam portions (58, 59), the other end of the second arm portion, and the second deflection portion are connected to each other, and are arranged to face each other with a predetermined gap. And a center of gravity (G11) of the first deflection unit and a center of gravity (G53) of the second deflection unit are on the optical path of the light. A two-dimensional optical deflector (100),
2) a first drive unit (20, 21, 93, 94) that swings the first deflecting unit about a line (x1) passing through the center of gravity of the pair of first beam portions; Second drive unit (66, 67) for swinging the second deflecting unit about a line (y2) that bisects the gap between the pair of second beam units and the pair of third beam units The two-dimensional optical deflector (100) according to 1), further comprising:
3) a third drive section (20, 21, 93, 94) that swings the first deflection section about an axis (x1) that passes through the center of gravity of the pair of first beam sections; The first deflecting unit is swung to apply vibration to the second deflecting unit, and the second deflecting unit is configured to have a gap between the pair of second beam units and the pair of third beam units. The two-dimensional optical deflector (400) according to 1), further comprising a fourth drive unit (420, 421, 493, 494) that swings about the bisecting line (y2).
4) The first deflection unit deflects the light at a resonance frequency of the resin or a frequency lower than the resonance frequency, and the second deflection unit deflects the light at a resonance frequency of Si. The two-dimensional optical deflector according to any one of 1) to 3), which is characterized in that
5) The two-dimensional optical deflector according to any one of 1) to 4), a semiconductor laser element (310) that irradiates the mirror part with the light, and luminance modulation of the semiconductor laser element according to image information An image display device (300) having a luminance modulation section (320).
6) The image (G) is displayed by deflecting the light in the horizontal direction with the second light deflection element and deflecting the light in the vertical direction with the first light deflection element 3) It is an image display apparatus of description.

  According to the present invention, a high-resolution image can be displayed, the vertical scanning speed can be adjusted according to the frame rate, and there is an effect of having impact resistance.

It is a figure for demonstrating the structure of the two-dimensional optical deflector in Example 1 of this invention. It is a figure for demonstrating the optical deflection | deviation element 10 in Example 1 of this invention. It is a figure for demonstrating the optical deflection | deviation element 50 in Example 1 of this invention. FIG. 3 is a block diagram illustrating a drive control circuit for driving the optical deflection element 50 according to the first embodiment. It is a figure which shows the frequency characteristic of a light deflection element (resin) and a light deflection element (Si). It is a figure for demonstrating the structure of the two-dimensional optical deflector in Example 2 of this invention. It is a figure for demonstrating the optical deflection | deviation element 410 in Example 2 of this invention. FIG. 10 is a block diagram illustrating a drive control circuit for driving a mirror unit 63 in Embodiment 2. FIG. 10 is a schematic cross-sectional view showing a state in which the optical deflection element 50 in Example 2 is driven to be excited. It is a typical block diagram for demonstrating the Example of the image display apparatus which concerns on this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to FIGS. 1 to 10 according to preferred embodiments 1 and 2. FIG.

<Example 1>
[Configuration of two-dimensional optical deflector]
First, the configuration of the two-dimensional optical deflector in Embodiment 1 of the present invention will be described with reference to FIG.
1A and 1B are diagrams for explaining the configuration of a two-dimensional optical deflector according to the first embodiment of the present invention. FIG. 1A is a plan view when viewed from the mirror side, and FIG. A side view when seen from the direction of arrow S1 in (a), (c) is a schematic cross-sectional view taken along line y2 in (a).

  As shown in FIG. 1, the two-dimensional optical deflector 100 mainly includes a support body 1 having a substantially U-shaped cross section, an optical deflection element 10 supported by the support body 1, and fixed on the optical deflection element 10. And the electromagnetic coil unit 90 that is fixed to the support 1 and drives the optical deflection element 10.

Here, the optical deflection element 10 will be described in detail with reference to FIG.
2A and 2B are diagrams for explaining the optical deflection element 10 in the two-dimensional optical deflector of the first embodiment. FIGS. 2A, 2B, and 2C in FIG. ), (B), and (c), respectively.

  As shown in FIG. 2, the optical deflection element 10 mainly includes a deflection unit 11 for deflecting a laser beam L described later in a vertical direction {corresponding to the vertical direction in FIG. 2A) of an image G described later. The terminal portions 13 and 14 arranged to face each other via the deflection portion 11, the beam portion 16 that connects the terminal portion 13 and the deflection portion 11, and the beam portion 17 that connects the terminal portion 14 and the deflection portion 11, The magnet base 19 is fixed to a surface B11 opposite to the surface A11 to which the light deflecting element 50 is fixed in the deflecting unit 11 {the back surface in FIG. 2A}, and further separated from the magnet base 19 from each other. And a pair of permanent magnets 20 and 21 fixed thereto.

  The deflection unit 11 has electrodes 23 and 24 in the vicinity of the beam portion 16, and electrodes 25 and 26 in the vicinity of the beam portion 17.

  The terminal portion 13 has electrodes 28 and 29, and the terminal portion 14 has electrodes 30 and 31.

The beam portion 16 includes a wiring 33 that electrically connects the electrode 23 and the electrode 28 and a wiring 34 that electrically connects the electrode 24 and the electrode 29.
The beam portion 17 includes a wiring 35 that electrically connects the electrode 25 and the electrode 30 and a wiring 36 that electrically connects the electrode 26 and the electrode 31.

The permanent magnet 20 and the permanent magnet 21 have the same polarity direction.
In FIGS. 1 and 2, the polarities of the permanent magnet 20 and the permanent magnet 21 are shown as the N pole on the side close to the electromagnetic coil unit 90 and the S pole on the far side, but the present invention is not limited to this. The side closer to the electromagnetic coil unit 90 may be the S pole, and the far side may be the N pole.
It is desirable to use a neodymium-based material having a large coercive force as the permanent magnets 20 and 21.
By using a neodymium-based material for the permanent magnets 20 and 21, the permanent magnets 20 and 21 can be made lighter and more compact, so that the deflection unit 11 can be driven with less driving force (power consumption). become.

  The light deflection element 10 includes a line x1 connecting the center of gravity of the beam portion 16 and the center of gravity of the beam portion 17 and the permanent magnet 20 when FIG. 1A and FIG. A line y1 connecting the center of gravity of the permanent magnet 21 and the center of gravity of the permanent magnet 21 passes through the center of gravity G11 of the deflecting unit 11, and the lines x1 and y1 are configured to be orthogonal to each other.

  A flexible soft resin such as polyimide or silicone resin can be used as the base material 38 of the optical deflecting element 10, and the optical deflecting element 10 is manufactured by using a known flexible wiring board manufacturing method. Can do.

Next, the optical deflection element 50 will be described in detail with reference to FIG.
FIG. 3 is a diagram for explaining the optical deflection element 50 in the two-dimensional optical deflector according to the first embodiment, and (a), (b), and (c) in FIG. ), (B), and (c), respectively.

  As shown in FIG. 3, the light deflection element 50 is mainly disposed in a frame-like support portion 52 and in the frame of the support portion 52 so as to be separated from the support portion 52, and an image that will be described later with laser light L that will be described later. A deflecting portion 53 for deflecting in the horizontal direction G (corresponding to the left-right direction in FIG. 3A) and one end side of each of the supporting portions 52 are connected to each other and arranged via the deflecting portion 53. A pair of arm portions 54, 55, a pair of arm portions 56, 57 disposed at one end side to the inner edge portion of the support portion 52 facing the one inner edge portion and disposed via the deflection portion 53, and the arm portion 54, respectively. A beam portion 58 connecting the other end side of the arm portion 55 and the deflection portion 53, a beam portion 59 connecting the other end side of the arm portion 55 and the deflection portion 53, and the other end side of the arm portion 56 and the deflection portion 53. The beam portion 60 to be connected, the other end side of the arm portion 57 and the deflection portion 53 are connected. It is configured to include the parts 61, the.

The deflecting unit 53 is a reflective film mainly composed of a highly reflective metal such as Al (aluminum) or Au (gold) on the surface opposite to the side where the light deflecting element 50 is fixed to the light deflecting element 10. Has a mirror part 63 formed thereon.
The mirror unit 63 reflects the laser light L emitted from the semiconductor laser element 310 in the image display device 300 described later.

The arm portions 54, 55, 56, 57 have piezoelectric elements 66, 67, 68, 69 formed on one surface side corresponding to the respective arm portions.
Each of the piezoelectric elements 66, 67, 68, and 69 has a laminated structure in which a lower electrode, a piezoelectric film, and an upper electrode are sequentially laminated. A voltage is applied between the upper electrode and the lower electrode to apply the piezoelectric element. By vibrating 66, 67, 68, 69, the arm portions 54, 55, 56, 57 can be vibrated correspondingly.

  The support portion 52 is formed on one surface side thereof, and is electrically connected to each upper electrode of the piezoelectric elements 66 and 67 via a wiring (not shown) and illustrated on each lower electrode of the piezoelectric elements 66 and 67. Electrode 72 electrically connected to the upper electrode of the piezoelectric elements 68 and 69, electrode 73 electrically connected to the upper electrodes of the piezoelectric elements 68 and 69, and lower electrodes of the piezoelectric elements 68 and 69, respectively. And an electrode 74 electrically connected via a wiring (not shown).

  The light deflection element 50 is a line that bisects the gap between the beam portion 58 and the beam portion 60 and bisects the gap between the beam portion 59 and the beam portion 61 when FIG. y <b> 2 is configured to pass through the center of gravity G <b> 53 of the deflecting unit 53.

  Further, in the optical deflection element 50, the deflection portion 53, the arm portions 54, 55, 56, 57 and the beam portions 58, 59, 60, 61 are made thinner than the support portion 52.

  The optical deflection element 50 described above can be manufactured by using a known semiconductor process, for example, an Si (silicon) wafer such as SOI (Silicon on Insulator).

  Next, the relationship between the optical deflection element 10 and the optical deflection element 50 will be described with reference back to FIG.

In FIG. 1A, a laser beam L, which will be described later, is emitted toward the mirror unit 63 from the front side of the paper, but the center of gravity G53 of the deflection unit 53 of the optical deflection element 50 and the deflection unit 11 of the optical deflection element 10 are irradiated. The optical deflection element 50 is arranged so that the center of gravity G11 is positioned on the optical path of the laser light L (on the extension line of the optical path) and the line y2 of the optical deflection element 50 is orthogonal to the line x1 of the optical deflection element 10. It is fixed to the surface A11 of the deflection unit 11 of the optical deflection element 10.
In addition, the optical deflection element 10 and the optical deflection element 50 include an electrode 23 and an electrode 71, an electrode 24 and an electrode 72, an electrode 25 and an electrode 73, an electrode 26 and an electrode 74, Are electrically connected via gold wires 80, for example.

  Next, the electromagnetic coil unit 90 will be described with reference to FIG.

  As shown in FIG. 1, the electromagnetic coil unit 90 mainly includes a coil base 92 and a pair of coils 93 and 94 fixed to the coil base 92. The coils 93 and 94 are air core winding coils.

The coil 93 corresponds to the permanent magnet 20, and the coil 94 corresponds to the permanent magnet 21 and is fixed to the coil base 92.
Further, the coil 93 and the coil 94 are respectively fixed to the coil base 92 so as not to come into contact with the permanent magnet 20 and the permanent magnet 21 when the deflecting unit 11 is driven in the vertical direction.
In addition, the coil 93 and the coil 94 are connected in series, for example, via a wiring (not shown) so that the directions of the magnetic lines of force generated when energizing them are opposite to each other.

[Driving method of two-dimensional optical deflector]
Next, a method for driving the above-described two-dimensional optical deflector 100 will be described with reference to FIGS.
4 is a block diagram showing a drive control circuit for driving the optical deflection element 50 in the two-dimensional optical deflector 100, and FIG. 5 is a diagram showing frequency characteristics of the optical deflection element 10 and the optical deflection element 50. It is.

  First, a method of driving the mirror unit 63 (deflection unit 53) of the above-described two-dimensional optical deflector 100 in the horizontal direction {left and right direction in FIGS. 1A and 3A} will be described with reference to FIGS. This will be described with reference to FIGS.

  First, a drive control circuit for controlling the horizontal drive of the mirror unit 63 (deflection unit 53) will be described with reference to FIG.

  As shown in FIG. 4, the drive control circuit 200 mainly includes an amplifier 201, a noise removal filter (for example, a low-pass filter) 202, a phase adjuster 203, an automatic gain control circuit (hereinafter referred to as an AGC circuit) 204, and a drive amplifier. 205.

The amplifier 201 has an input side connected to the electrode 30 and the electrode 31 of the terminal unit 14 in the two-dimensional optical deflection element 100, and an output side connected to the noise removal filter 202.
The output side of the noise removal filter 202 is connected to the phase adjuster 203, the output side of the phase adjuster 203 is connected to the AGC circuit 204, and the output side of the AGC circuit 204 is connected to the drive amplifier 205.
The output side of the drive amplifier 205 is connected to the electrode 28 and the electrode 29 of the terminal portion 13 in the two-dimensional optical deflection element 100.

The resonance drive signal Dh output from the drive amplifier 205 is input to the piezoelectric element 66 and the piezoelectric element 67 of the light deflection element 50 through the electrode 28 and the electrode 29.
As the arm portion 54 and the arm portion 55 vibrate, the mirror portion 63 (deflection portion 53) is driven in the horizontal direction in the primary rotation mode with the line y2 (see FIGS. 1 and 3) as the rotation axis. To do.
Further, when the mirror unit 63 (deflection unit 53) is driven, stress distortion occurs in the piezoelectric element 68 and the piezoelectric element 69, and a voltage corresponding to the stress distortion is generated.
This voltage is amplified by the amplifier 201 and output as the detection signal Sn.
For example, the detection signal Sn and the resonance drive signal Dh have a specific phase difference in the resonance mode with the resonance drive signal Dh by the phase adjuster 203 after the noise component is removed by the noise removal filter 202. Are phase-adjusted so that they are 180 degrees out of phase with each other.
The phase-adjusted detection signal Sn is adjusted so that the amplitude of the sine wave generated by the AGC circuit 204 is constant, and then boosted to a predetermined value by the drive amplifier 205, and the resonance drive signal Dh This is input to the piezoelectric element 66 and the piezoelectric element 67 through the electrode 29.

  As described above, the optical deflection element 50 is mainly composed of silicon. As shown in FIG. 5, since the resonance frequency of silicon is as high as several tens of kHz, the piezoelectric resonance frequency of silicon is reduced between the piezoelectric element 66 and the piezoelectric element 67. By inputting the drive signal Dh having substantially the same frequency, the mirror unit 63 (deflection unit 53) can be resonantly driven in the horizontal direction and at high speed.

  The resonance drive signal Dh input to the piezoelectric element 66 and the piezoelectric element 67 by the two-dimensional optical deflector 100 and the drive control circuit 200 described above has a specific phase relationship with the detection signal Sn from the piezoelectric element 68 and the piezoelectric element 69. By performing the feedback loop control as described above, the mirror unit 63 (deflection unit 53) can always be driven at the resonance frequency.

  Next, a method of driving the mirror unit 63 of the above-described two-dimensional optical deflector 100 in the vertical direction {vertical direction in FIGS. 1A and 2A} will be described with reference to FIGS. .

By energizing the coil 93 and the coil 94, magnetic lines of force opposite to each other are generated in the coils 93 and 94.
Due to these lines of magnetic force, for example, the permanent magnet 20 is attracted to the coil 93 and the permanent magnet 21 is repelled from the coil 94, so that the deflection unit 11 is on the permanent magnet 20 side {the upper side in FIG. 1 (a) and FIG. } Is driven in a direction approaching the light deflection element 50.
Further, by reversing the direction of the current applied to the coil 93 and the coil 94, the deflecting unit 11 has the permanent magnet 21 side {lower side in FIG. 1 (a) and FIG. 2 (a)} on the optical deflection element. Drive in a direction approaching 50.

  Therefore, by alternately switching the direction of the current supplied to the coil 93 and the coil 94 at a predetermined cycle, the mirror unit 63 can be driven in the vertical direction with the line x1 as the rotation axis.

  Further, as described above, the light deflection element 10 is mainly composed of a flexible soft resin such as polyimide or silicone resin. As shown in FIG. 4, the resonance frequency of such a soft resin (FIG. 4). Shows a frequency characteristic of polyimide as an example), and soft resin has a low Q value because of its low elastic modulus. Therefore, by inputting a sinusoidal drive signal to coil 93 and coil 94 The deflection unit 11 can be driven with a sufficient deflection angle even in the resonance frequency of the soft resin and in the vicinity thereof, and in the non-resonance region lower than the resonance frequency.

  Therefore, the mirror unit 63 can be driven at a low speed in the vertical direction together with the light deflection element 10 by driving the optical deflection element 10 mainly composed of a soft resin in the vertical direction at low speed or non-resonance driving.

  According to the two-dimensional optical deflector 100 described above, the number thereof can be reduced as compared with the optical deflector disclosed in Patent Document 1 described above, and is disclosed in Patent Document 2 described above. Compared to such an optical deflector, the area of use of the Si substrate, which is an expensive material, can be reduced, so that the material cost of the element can be reduced.

  Further, according to the above-described two-dimensional optical deflector 100, in particular, the light deflection element 50 mainly composed of brittle Si is fixed to the light deflection element 10 mainly composed of a soft resin having excellent impact resistance, Since the optical deflection element 10 has a configuration supported by the support 1, when an impact is applied to the two-dimensional optical deflector 100 from the outside, the impact can be absorbed by the optical deflection element 10. Damage to the optical deflection element 50 can be prevented.

<Example 2>
[Configuration of two-dimensional optical deflector]
Next, the configuration of the two-dimensional optical deflector in Embodiment 2 of the present invention will be described with reference to FIG.
6A and 6B are diagrams for explaining the configuration of the two-dimensional optical deflector according to the second embodiment of the present invention, in which FIG. 6A is a plan view when viewed from the mirror portion side, and FIG. A side view when seen from the direction of arrow S2 in (a), (c) is a schematic cross-sectional view taken along line y2 in (a).
In order to make the description easy to understand, the same components as those in the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 6, the two-dimensional optical deflector 400 mainly includes a support body 401 having a substantially U-shaped cross section, an optical deflection element 410 supported by the support body 401, and fixed on the optical deflection element 410. And the electromagnetic coil unit 490 that is fixed to the support 401 and drives the optical deflection elements 410 and 50.

Here, the optical deflection element 410 will be described in detail with reference to FIG.
7A and 7B are diagrams for explaining the optical deflection element 410 in the two-dimensional optical deflector according to the second embodiment. FIGS. 7A, 7B, and 7C in FIG. ), (B), and (c), respectively.

  As shown in FIG. 7, the light deflection element 410 mainly includes a deflection unit 11 for deflecting a laser beam L described later in a vertical direction {corresponding to the vertical direction in FIG. 7A) of an image G described later. The terminal portions 13 and 14 arranged to face each other via the deflection portion 11, the beam portion 16 that connects the terminal portion 13 and the deflection portion 11, and the beam portion 17 that connects the terminal portion 14 and the deflection portion 11, The magnet base 419 is fixed to the surface B11 opposite to the surface A11 to which the light deflecting element 50 is fixed in the deflecting unit 11 {the back surface in FIG. 7A}, and further separated from the magnet base 419. And a pair of permanent magnets 420 and 421 which are fixed to the magnet base 419 separately from each other.

  The deflection unit 11 has electrodes 23 and 24 in the vicinity of the beam portion 16, and electrodes 25 and 26 in the vicinity of the beam portion 17.

  The terminal portion 13 has electrodes 28 and 29, and the terminal portion 14 has electrodes 30 and 31.

The beam portion 16 includes a wiring 33 that electrically connects the electrode 23 and the electrode 28 and a wiring 34 that electrically connects the electrode 24 and the electrode 29.
The beam portion 17 includes a wiring 35 that electrically connects the electrode 25 and the electrode 30 and a wiring 36 that electrically connects the electrode 26 and the electrode 31.

The permanent magnet 20 and the permanent magnet 21 have the same polarity direction, and the permanent magnet 420 and the permanent magnet 421 have the same polarity direction.
6 and 7, the polarities of the permanent magnet 20 and the permanent magnet 21 and the polarities of the permanent magnet 420 and the permanent magnet 421 are shown as the N pole on the side close to the electromagnetic coil unit 490 and the S pole on the far side, respectively. However, the present invention is not limited to this, and the side closer to the electromagnetic coil unit 490 may be the south pole and the far side may be the north pole.
As the permanent magnets 20 and 21 and the permanent magnets 420 and 421, it is desirable to use a neodymium-based material having a large coercive force.
By using a neodymium-based material for the permanent magnets 20 and 21 and the permanent magnets 420 and 421, the permanent magnets 20 and 21 and the permanent magnets 420 and 421 can be made lighter and smaller, respectively. It is possible to drive with a small driving force (power consumption).

The light deflection element 410 includes a line x1 connecting the center of gravity of the beam portion 16 and the center of gravity of the beam portion 17 and the center of gravity of the permanent magnet 20 when FIG. 1A and FIG. A line y1 connecting the center of gravity of the permanent magnet 21 and the center of gravity of the permanent magnet 21 passes through the center of gravity G11 of the deflecting unit 11, and the line x1 and the line y1 are configured to be orthogonal to each other.
The permanent magnet 420 and the permanent magnet 421 are arranged such that their center of gravity is located on the line x1.

  A flexible soft resin such as polyimide or silicone resin can be used as the base material 38 of the optical deflecting element 410, and the optical deflecting element 410 is manufactured by using a known flexible wiring board manufacturing method. Can do.

  The configuration of the optical deflection element 50 of the second embodiment shown in FIG. 6 is the same as the configuration of the optical deflection element 50 (see FIGS. 1 and 3) of the first embodiment described above, and a description thereof will be omitted.

  Next, the relationship between the light deflection element 410 and the light deflection element 50 will be described with reference to FIG.

In FIG. 6A, a laser beam L, which will be described later, is irradiated toward the mirror unit 63 from the front side of the paper, but the gravity center G53 of the deflection unit 53 of the light deflection element 50 and the deflection unit 11 of the light deflection element 410. The optical deflection element 50 is arranged so that the center of gravity G11 is positioned on the optical path of the laser light L (on the extension line of the optical path), and the line y2 of the optical deflection element 50 is orthogonal to the line x1 of the optical deflection element 410. It is fixed to the surface A11 of the deflection unit 11 of the optical deflection element 10.
The optical deflection element 410 and the optical deflection element 50 include the electrode 23 and the electrode 71, the electrode 24 and the electrode 72, the electrode 25 and the electrode 73, the electrode 26 and the electrode 74, and the like. Are electrically connected via gold wires 80, for example.

  Next, the electromagnetic coil unit 490 will be described with reference to FIG.

  As shown in FIG. 6, the electromagnetic coil unit 490 mainly includes a coil base 492, a pair of coils 93 and 94 fixed to the coil base 492, and a pair of coils 493 and 494 similarly fixed to the coil base 492. And is configured. The coils 93 and 94 and the coils 493 and 494 are air core winding coils, respectively.

The coil 93 corresponds to the permanent magnet 20, the coil 94 corresponds to the permanent magnet 21, the coil 493 corresponds to the permanent magnet 420, and the coil 494 corresponds to the permanent magnet 421, respectively. It is fixed to.
In addition, the coil 93 and the coil 94 are fixed to the coil base 492 so as not to come into contact with the permanent magnet 20 and the permanent magnet 21 when the deflecting unit 11 is driven in the vertical direction, respectively. The deflection unit 11 is fixed to the coil base 492 so as not to come into contact with the permanent magnet 420 and the permanent magnet 421, particularly when driven in the horizontal direction.
In addition, the coil 93 and the coil 94 are connected in series, for example, via a wiring (not shown) so that the directions of the magnetic lines of force generated when energizing them are opposite to each other.
In addition, the coil 493 and the coil 494 are connected in series, for example, via a wiring (not shown) so that the directions of the magnetic lines of force generated when energizing them are opposite to each other.

[Driving method of two-dimensional optical deflector]
Next, a method for driving the above-described two-dimensional optical deflector 400 will be described with reference to FIGS.
FIG. 8 is a block diagram showing a drive control circuit for exciting and driving the optical deflection element 50 in the two-dimensional optical deflector 400. FIG. 9 is a schematic cross-sectional view showing a state in which the optical deflection element 50 is driven to vibrate, and FIGS. 9A and 9B correspond to FIG. 6B, respectively.

  A method of driving the mirror unit 63 of the above-described two-dimensional optical deflector 400 in the horizontal direction {left-right direction in FIGS. 6A and 3A} will be described with reference to FIGS. To do.

  First, a drive control circuit for controlling the horizontal drive of the mirror unit 63 will be described with reference to FIG.

  As shown in FIG. 8, the drive control circuit 500 mainly includes amplifiers 211 and 216, an adder circuit 217, a noise removal filter (for example, a low-pass filter) 212, a phase adjuster 213, an oscillation circuit 214, and a drive amplifier. 215.

The amplifier 211 has an input side connected to the electrode 30 and the electrode 31 of the terminal unit 14 in the two-dimensional optical deflection element 400, and an output side connected to the adder circuit 217.
The input side of the amplifier 216 is connected to the electrode 28 and the electrode 29 of the terminal unit 13 in the two-dimensional optical deflection element 400, and the output side is connected to the addition circuit 217.
The adder circuit 217 is connected to the noise removal filter 212 on the output side, the output side of the noise removal filter 212 is connected to the phase adjuster 213, and the output side of the phase adjuster 213 is connected to the oscillation circuit 214. The output side of the circuit 214 is connected to the drive amplifier 215.
The output side of the drive amplifier 215 is connected in series to the coil 493 and the coil 494 (see FIG. 6) in the two-dimensional optical deflection element 400.

The drive control circuit 500 is designed with a polarity relationship in which signals (voltages) input to the amplifier 211 and the amplifier 216 are in phase with each other when the mirror unit 63 (deflection unit 53) is driven to resonate.
Therefore, the detection signal Sn1 and the detection signal Sn2 output from the amplifier 211 and the amplifier 216 are sine waves having the same phase.
The detection signal Sn1 and the detection signal Sn2 are added by the adder circuit 217, and output as the resonance excitation drive signal Dm from the drive amplifier 215 via the noise removal filter 212, the phase adjuster 213, and the oscillation circuit 214.
The resonance excitation drive signal Dm is input to the coil 493 and the coil 494 (see FIG. 6) connected in series to each other in the two-dimensional optical deflection element 400.

  Next, a drive control method for controlling the horizontal drive of the mirror part 63 will be described with reference to FIG. 9 together with FIG.

The resonance excitation drive signal Dm is input to the coils 493 and 494, and magnetic lines of force opposite to each other are generated in the coils 493 and 494.
By the way, since the base material 38 of the light deflection element 410 is made of a flexible soft resin such as polyimide or silicone resin, the beam portions 16 and 17 of the light deflection element 50 are bent (elastic) by the lines of magnetic force. After the deformation, the state shown in FIG. 9A and the state shown in FIG. 9B are alternately and repeatedly driven.
Then, by setting the resonance excitation drive signal Dm to substantially the same frequency as the resonance frequency of silicon (see FIG. 5), the mirror unit 63 (deflection unit 53) uses the line y2 (see FIG. 3) as the rotation axis. Resonance excitation drive is performed at high speed in the horizontal direction in the primary rotation mode.

When the mirror unit 63 (deflection unit 53) is driven, stress distortion occurs in the piezoelectric elements 66 and 67 and the piezoelectric elements 68 and 69, respectively. Therefore, the piezoelectric elements 66 and 67 and the piezoelectric elements 68 and 69 correspond to the amount of stress strain. Voltage is generated.
The voltage generated in the piezoelectric elements 66 and 67 and the voltage generated in the piezoelectric elements 68 and 69 are in opposite phases. The voltage generated by the piezoelectric elements 66 and 67 is amplified by the amplifier 216 and output as the detection signal Sn2, and the voltage generated by the piezoelectric elements 68 and 69 is amplified by the amplifier 211 and output as the detection signal Sn1.
The detection signal Sn1 and the detection signal Sn2 are added by the addition circuit 217, the noise component is removed by the noise removal filter 212, and the phase difference from the sine wave generated by the resonance circuit 214 becomes a predetermined value. Adjusted.

  The reason why the detection signal Sn1 and the detection signal Sn2 are added is to extract the output from the piezoelectric elements 66, 67, 68, 69 more stably. Only the detection signal (Sn1 or Sn2) may be extracted.

The phase-adjusted detection signals Sn1 and Sn2 are amplified by the drive amplifier and output to the coils 493 and 494 as the resonance excitation drive signal Dm.
Then, the mirror part 63 (deflection part 53) is driven by the lines of magnetic force generated in the coils 493 and 494, and the voltage of the piezoelectric elements 66 and 67 and the voltage of the piezoelectric elements 68 and 69 generated thereby are feedback loop controlled. The horizontal driving of the mirror unit 63 (deflection unit 53) can always be controlled to the resonance frequency.

  In addition, according to the driving method of the second embodiment, the mirror unit can be driven at a lower voltage than the piezoelectric driving method of the first embodiment, in particular, by using an electromagnetic coil as the driving source of the light deflection element 50.

  The method for driving the mirror unit 63 of the above-described two-dimensional optical deflector 400 in the vertical direction {vertical direction in FIG. 6A} is the same as the driving method of the above-described first embodiment, and thus the description thereof is omitted. To do.

  According to the two-dimensional optical deflector 400 described above, the number thereof can be reduced as compared with the optical deflector disclosed in Patent Document 1 described above, and is disclosed in Patent Document 2 described above. Compared to such an optical deflector, the area of use of the Si substrate, which is an expensive material, can be reduced, so that the material cost of the element can be reduced.

  Further, according to the above-described two-dimensional optical deflector 400, in particular, the light deflection element 50 whose main component is brittle Si is fixed to the light deflection element 410 whose main component is a soft resin excellent in impact resistance, Since the optical deflection element 410 has a configuration supported by the support 401, when an impact is applied to the two-dimensional optical deflector 400 from the outside, the impact can be absorbed by the optical deflection element 410. Damage to the optical deflection element 50 can be prevented.

[Image display device using two-dimensional optical deflector]
Next, an image display apparatus using the above-described two-dimensional optical deflectors 100 and 400 will be described with reference to FIG.
FIG. 10 is a schematic configuration diagram for explaining an embodiment of the image display apparatus according to the present invention.

  As shown in FIG. 10, the image display apparatus 300 mainly includes a laser beam toward the two-dimensional optical deflector 100 or the two-dimensional optical deflector 400 described above and the mirror unit 63 of the two-dimensional optical deflector 100 (400). A semiconductor laser element 310 that emits light L and a luminance modulation unit 320 that modulates the luminance of the semiconductor laser element 310 according to image information are configured.

  Next, a display method for displaying the image G on the screen P using the image display device 300 will be described with reference to FIG.

The two-dimensional light is supplied from the luminance modulation unit 320 to the semiconductor laser element 310 to emit laser light L from the semiconductor laser element 310 and the emitted laser light L is modulated in luminance according to image information of each pixel. Irradiate the mirror unit 63 of the deflector 100 (400).
In addition, luminance modulation is performed in synchronization with the light deflection element 50 and the light deflection element 10 (410) of the two-dimensional optical deflector 100 (400) driven by the above-described driving method.
The laser beam L irradiated to the mirror unit 63 is deflected in the horizontal direction by the light deflection element 50 and deflected in the vertical direction by the light deflection element 10 (410).
Raster scan while synchronizing the output intensity of the laser light L emitted from the semiconductor laser element 310 and the deflection angles of the second light deflection element 50 and the first light deflection element 10 according to the image information of each pixel. As a result, the image G is displayed on the screen P.

  In the image display apparatus 300 described above, if an element that emits red laser light is used as the semiconductor laser element 310, a red (R) monochromatic image is displayed, and if an element that emits green laser light is used, green (G ) And a blue (B) monochromatic image is displayed if an element that emits blue laser light is used.

  As a modification of the image display device 300 described above, three semiconductor laser elements that emit these three colors of laser light and optical components such as a dichroic prism and a dichroic mirror that synthesize each laser light into one beam. And a two-dimensional optical deflector 100, and a three-color (R, G, B) image is superimposed on the screen P and displayed, so that a full-color image can be displayed.

  According to the image display device 300 described above, in particular, the laser light L emitted from the semiconductor laser element 310 is deflected at high speed in the horizontal direction by the light deflecting element 50, and in the vertical direction by the light deflecting element 10 (410). Since it is deflected at a low speed, a high-resolution image can be displayed.

  In addition, according to the image display device 300 described above, the optical deflection element 10 (410) can be driven in a wide frequency range below the resonance frequency of the soft resin, so that the scanning speed can be adjusted according to the frame rate. It can be done easily.

  The embodiment of the present invention is not limited to the configuration and procedure described above, and it goes without saying that modifications may be made without departing from the scope of the present invention.

  For example, in the first and second embodiments, in the two-dimensional optical deflector 100 (400), the polarities of the permanent magnet 20 and the permanent magnet 21 (and the polarities of the permanent magnet 420 and the permanent magnet 421) are the same, and the coil 93 and the coil 94 are different in the direction of the magnetic lines of force (and the direction of the magnetic lines of force between the coils 493 and 494). However, the present invention is not limited to this, and the polarities of the permanent magnet 20 and the permanent magnet 21 ( Further, the polarities of the permanent magnet 420 and the permanent magnet 421) may be different from each other, and the direction of the magnetic force lines of the coil 93 and the coil 94 (and the direction of the magnetic force lines of the coil 493 and the coil 494) may be the same.

  In the first embodiment, in the two-dimensional optical deflector 100, the arm portion 54 and the arm portion 55 are driven by the piezoelectric element 66 and the piezoelectric element 67, and the vibration state of the deflection portion 53 is detected by the piezoelectric element 68 and the piezoelectric element 69. However, the present invention is not limited to this, and the arm portion 56 and the arm portion 57 are driven by the piezoelectric element 68 and the piezoelectric element 69, and the vibration state of the deflection unit 53 is detected by the piezoelectric element 66 and the piezoelectric element 67. It is good also as composition to do.

In particular, when it is not necessary to detect the vibration state of the second deflection unit 53 (for example, when displaying an image with a resolution that is not so high), the arm unit 54 is used by using the piezoelectric elements 66, 67, 68, and 69. The arm portion 55 and the arm portion 56 and the arm portion 57 may be driven in opposite phases.
Thereby, a wider deflection angle than that of the first embodiment can be obtained.

  Moreover, in Example 1 and Example 2, the permanent magnets 20 and 21 (and the permanent magnets 420 and 421) are provided in the light deflection element 10 (410), and the coils 93 and 94 are provided in the electromagnetic coil unit 90 (490). However, the present invention is not limited to this. The coils 93 and 94 are provided in the optical deflection element 10 (410), and the permanent magnets 20 and 21 (and the permanent magnets 420 and 421) are provided in the electromagnetic coil unit 90 (490). It is good also as a structure which provided.

  In the first and second embodiments, the electrodes 23, 24, 25, and 26 of the light deflection element 10 (410) and the electrodes 71, 72, 73, and 74 of the light deflection element 50 are connected by the gold wire 80. However, the present invention is not limited to this, and the electrodes 23, 24, 25, and 26 of the optical deflection element 10 (410) and the electrodes 71, 72, 73, and 74 of the optical deflection element 50 are electrically connected. The connection method is not particularly limited.

  In the first and second embodiments, the deflecting direction of the optical deflecting element 10 (410) and the deflecting direction of the optical deflecting element 50 are orthogonal to each other. However, the present invention is not limited to this. It is only necessary that the deflection direction of the optical deflection element 10 (410) and the deflection direction of the optical deflection element 50 are different from each other.

  The two-dimensional optical deflector and the image display apparatus using the same according to the present invention are particularly useful for a projection-type image display system that displays an image by a raster scan method. The two-dimensional optical deflector according to the present invention can also be applied to a laser printer, a two-dimensional barcode reader, and the like.

DESCRIPTION OF SYMBOLS 1_ Support body, 10, 50_ Light deflection element, 11, 53_ Deflection part, 13, 14_ Terminal part, 16, 17, 58, 59, 60, 61_ Beam part, 19_ Magnet base, 20, 21_ Permanent magnet, 23, 24 , 25, 26, 28, 29, 30, 31, 71, 72, 73, 74_ electrodes, 33, 34, 35, 36_ wiring, 38_ base material, 52_ support part, 54, 55, 56, 57_ arm part, 63_ Mirror part, 66,67,68,69_piezoelectric element, 80_gold wire, 90_electromagnetic coil unit, 92_coil base, 93,94_coil, 100_2 two-dimensional optical deflector, 200_drive control circuit, 201_amplifier, 202_noise removal filter, 203_phase adjuster, 204_automatic gain control circuit (AGC circuit), 205_drive amplifier, 300_image display device, 310_semiconductor laser element, 320_brightness modulation unit, A11, B11_plane, x1, y1, y2_ line, G11, G53_center of gravity, L_laser light, G_image, P_screen

Claims (6)

In a two-dimensional optical deflector,
A first light deflection element that includes resin and deflects light emitted from the outside in one direction;
A second light deflection element that includes Si (silicon) and deflects the light in another direction different from the one direction;
With
The first light deflection element is:
A pair of terminal portions that are disposed opposite to each other, and
A first deflection unit disposed between the pair of terminal units;
A pair of first beam portions respectively connecting the first deflecting portion and the pair of terminal portions;
Have
The second light deflection element is
A frame-like support portion fixed on the first deflection portion;
A second deflecting unit disposed in a frame of the support unit and spaced apart from the first deflecting unit and having a mirror unit for reflecting the light;
A pair of first arm portions disposed on both sides of the second deflection unit and having one ends connected to the support unit;
A pair of second arm portions disposed on opposite sides of the second deflection portion so as to face the first arm portion, and having one end connected to the support portion;
A pair of second beam portions respectively connecting the other end of the first arm portion and the second deflection portion;
A pair of third beam portions that connect each other end of the second arm portion and the second deflection portion, respectively, and are arranged to face each other with a predetermined gap between the second beam portions, ,
Have
The two-dimensional optical deflector characterized in that the center of gravity of the first deflecting unit and the center of gravity of the second deflecting unit are located on the optical path of the light. A first drive unit that swings the first deflecting unit around a line passing through each center of gravity of the pair of first beam portions;
A second drive unit that swings the second deflecting unit about a line that bisects the gap between the pair of second beam units and the pair of third beam units;
The two-dimensional optical deflector according to claim 1, further comprising: A third drive unit that swings the first deflecting unit about a line passing through each center of gravity of the pair of first beam portions;
The first deflecting unit is swung to apply vibration to the second deflecting unit, and the second deflecting unit is disposed between the pair of second beam units and the pair of third beam units. A fourth drive unit that swings about a line that bisects the line;
The two-dimensional optical deflector according to claim 1, further comprising: The first deflection unit deflects the light at a resonance frequency of the resin or a frequency lower than the resonance frequency,
4. The two-dimensional optical deflector according to claim 1, wherein the second deflecting unit deflects the light at a resonance frequency of Si. 5. The two-dimensional optical deflector according to any one of claims 1 to 4,
A semiconductor laser element for irradiating the mirror part with the light;
A luminance modulation section for modulating the luminance of the semiconductor laser element according to image information;
An image display apparatus.   6. The image display according to claim 5, wherein the image is displayed by deflecting the light in a horizontal direction by the second light deflection element and deflecting the light in a vertical direction by the first light deflection element. apparatus.

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