JP2008298829A - Optical reflection element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize an optical reflection element having a piezoelectric oscillation plate. <P>SOLUTION: The optical reflection element has: a frame body 17 supported by a frame body 14 by means of a serpentine support part 16A provided in a groove 15; and an optical reflection part 20 supported on the frame body 17 by means of a serpentine support part 19A provided in a groove 18, wherein the serpentine support part 16A has a rectangular piezoelectric oscillation plate 21A and a rectangular piezoelectric oscillation plate 22A, the serpentine supporting part 19A has a rectangular piezoelectric oscillation plate 26A and a rectangular piezoelectric oscillation plate 27A, the oscillation phase at the rectangular piezoelectric oscillation plate 21A and the oscillation phase at the rectangular piezoelectric oscillation plate 22A is shifted by 180 degrees, and the oscillation phase at the rectangular piezoelectric oscillation plate 26A and the oscillation phase at the rectangular piezoelectric oscillation plate 27A is shifted by 180 degrees. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical reflection element used in an optical reflection projection apparatus using laser light.

  Conventionally, as shown in FIG. 6, this type of optical reflecting element is supported by the frame 1 by a frame 1, and the frame 1 separated by a groove 2 and supported by a support shaft 3 provided in the groove 2. One end of the frame 4 is connected to the frame body 1, the optical reflector 7 separated from the frame body 4 by the groove 5 and supported by the support shaft 6 provided in the groove 5. In addition, piezoelectric vibration plates 8 and 9 having other ends connected to the support shaft 3 and piezoelectric vibration plates 10 and 11 having one end connected to the frame body 4 and the other end connected to the support shaft 6 are connected. The support shaft 6 is provided so that the axial direction of the support shaft 3 is perpendicular to the support shaft 3, and the frame 4 is pivoted about the support shaft 3, and the optical reflecting portion 7 is pivoted about the support shaft 6. 7, the configuration in which the reflected light of the light 12 incident on the optical reflecting unit 7 is scanned two-dimensionally on the screen 13 is realized. It was.

As prior art document information relating to this application, for example, Patent Document 1 is known.
JP 2005-148459 A

  In such a conventional optical reflecting element, it has been a problem that miniaturization is difficult.

  That is, in the above-described conventional configuration, a predetermined voltage is applied to the electrodes 8A, 9A, 10A, and 11A arranged on the piezoelectric diaphragms 8, 9, 10, and 11, and the piezoelectric diaphragms 8, 9, 10, and 11 are attached. In order to bend at a predetermined angle, it is necessary to secure the lengths of the electrodes 8A, 9A, 10A, and 11A. As a result, it has been difficult to reduce the size.

  Accordingly, an object of the present invention is to realize miniaturization of an optical reflection element having a piezoelectric diaphragm.

  In order to achieve this object, the present invention provides a first frame and a first meander that is separated in the first frame by a first groove and is provided in the first groove. A second frame supported by the first frame body by the shape support portion, and a second frame provided in the second groove and separated by the second groove in the second frame body And an optical reflecting portion supported by the second frame by means of a meandering support, wherein the first meandering support is at least a first rectangular piezoelectric diaphragm and the first rectangular piezoelectric diaphragm. And a second rectangular piezoelectric diaphragm having one end connected to one end of the first rectangular piezoelectric diaphragm, wherein the second meandering support portion is at least A third rectangular piezoelectric diaphragm provided in a direction substantially perpendicular to the first rectangular piezoelectric diaphragm. A fourth rectangular piezoelectric diaphragm provided substantially parallel to the third rectangular piezoelectric diaphragm and having one end connected to one end of the third rectangular piezoelectric diaphragm, The phase of vibration in the first rectangular piezoelectric diaphragm and the phase of vibration in the second rectangular piezoelectric diaphragm are shifted by 180 degrees, and the phase of vibration in the third rectangular piezoelectric diaphragm and the fourth rectangle This is an optical reflecting element in which the phase of vibration in the piezoelectric plate is shifted by 180 degrees.

  With this configuration, in the optical reflecting element of the present invention, the bending directions of the first and second rectangular piezoelectric plates in the first meandering support portion are staggered, and the third in the second meandering support portion. Since the bending directions of the fourth rectangular piezoelectric diaphragms are staggered, even if the length of the rectangular piezoelectric diaphragm is reduced, the bending angle is added by the number of rectangular piezoelectric diaphragms. The bending at a predetermined angle can be obtained in the meandering support portion, and as a result, the optical reflecting element can be miniaturized.

(Embodiment 1)
Hereinafter, the optical reflecting element according to Embodiment 1 of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the optical reflecting element in the present embodiment is separated by a frame 14 and a groove 15 in the frame 14, and meandering support portions 16 </ b> A and 16 </ b> B provided in the groove 15. And a frame body 17 supported by the frame body 14.

  The frame body 17 includes an optical reflecting portion 20 that is separated by a groove 18 and supported by the frame body 17 by meandering support portions 19A and 19B provided in the groove 18.

  The meandering support 16A is a rectangular piezoelectric diaphragm 21A, 22A, 23A, 24A, 25A, and the serpentine support 16B is a rectangular piezoelectric diaphragm 21B, 22B, 23B, 24B, 25B. 19A has rectangular piezoelectric diaphragms 26A, 27A, 28A, and 29A, and the meandering support portion 19B has rectangular piezoelectric diaphragms 26B, 27B, 28B, and 29B.

  Here, the rectangular piezoelectric diaphragms 22A, 23A, 24A, and 25A are all arranged in a direction substantially parallel to the rectangular piezoelectric diaphragm 21A, and one end of the rectangular piezoelectric diaphragm 21A is the rectangular piezoelectric diaphragm 22A. The other end of the rectangular piezoelectric diaphragm 22A is one end of the rectangular piezoelectric diaphragm 23A, the other end of the rectangular piezoelectric diaphragm 23A is one end of the rectangular piezoelectric diaphragm 24A, and the rectangular piezoelectric diaphragm 24A. Is connected to one end of the rectangular piezoelectric diaphragm 25A.

  Similarly, the rectangular piezoelectric diaphragms 22B, 23B, 24B, and 25B are all arranged in a direction substantially parallel to the rectangular piezoelectric diaphragm 21B, and one end of the rectangular piezoelectric diaphragm 21B is the rectangular piezoelectric diaphragm 22B. The other end of the rectangular piezoelectric diaphragm 22B is one end of the rectangular piezoelectric diaphragm 23B, the other end of the rectangular piezoelectric diaphragm 23B is one end of the rectangular piezoelectric diaphragm 24B, and the rectangular piezoelectric diaphragm 24B. Is connected to one end of a rectangular piezoelectric diaphragm 25B.

  Further, the rectangular piezoelectric diaphragms 26A, 27A, 28A, 29A are all arranged substantially perpendicular to the rectangular piezoelectric diaphragm 21A, and one end of the rectangular piezoelectric diaphragm 26A is the same as the rectangular piezoelectric diaphragm 27A. One end, the other end of the rectangular piezoelectric diaphragm 27A is one end of the rectangular piezoelectric diaphragm 28A, the other end of the rectangular piezoelectric diaphragm 28A is one end of the rectangular piezoelectric diaphragm 29A, and the rectangular piezoelectric diaphragm 29A. The other end is connected to one end of the rectangular piezoelectric diaphragm 30A.

  Similarly, the rectangular piezoelectric diaphragms 26B, 27B, 28B, and 29B are all disposed substantially perpendicular to the rectangular piezoelectric diaphragm 21B, and one end of the rectangular piezoelectric diaphragm 26B is a rectangular piezoelectric diaphragm 27B. The other end of the rectangular piezoelectric diaphragm 27B is one end of the rectangular piezoelectric diaphragm 28B, the other end of the rectangular piezoelectric diaphragm 28B is one end of the rectangular piezoelectric diaphragm 29B, and the rectangular piezoelectric diaphragm 29B. Is connected to one end of the rectangular piezoelectric diaphragm 30B.

  As shown in FIG. 2, which is an enlarged view of the A part of FIG. 1, these rectangular piezoelectric diaphragms 21A and 23A have electrodes 30 on their upper surfaces, and the rectangular piezoelectric diaphragm 22A has electrodes 31 on their upper surfaces. And are electrically connected to the electrodes 30A and 31A shown in FIG.

  These rectangular piezoelectric diaphragms 21A, 22A, and 23A have a common silicon substrate 34 on the bottom surface thereof as shown in FIG. 3 which is a cross-sectional view taken along the line B-BB in FIG. The oxide film 35 is further provided with an electrode 32 provided in common thereon, and further provided with a piezoelectric layer 33 provided in common thereon, and the above-described electrode 30A or electrode 31A is provided on the upper surface of the piezoelectric layer 33. It is configured. The electrode 32 is electrically connected to the electrode 32A shown in FIG.

  As described above, the meandering support portions 16A, 16B, 19A, and 19B employ a configuration in which the electrodes 30 and 31 formed on the upper surface of the piezoelectric layer 33 are alternately arranged for each adjacent rectangular piezoelectric diaphragm. ing.

  Next, the operation principle of the optical reflecting element in the present embodiment will be described.

  First, an alternating voltage is applied to the electrodes 30A and 31A shown in FIG. 1 with the phase shifted by 180 degrees, and the electrode 32A is grounded.

  Then, as shown in FIG. 3, at a certain point in time, for example, when a positive potential is applied to the electrode 30, a negative potential is applied to the electrode 31, and the electrode 32 is in a grounded state. Between the vibration plates 21A and 23A and the rectangular piezoelectric vibration plate 22A, voltages in opposite directions are applied to the respective piezoelectric layers 33.

  Since the bending direction of the piezoelectric device 33 changes depending on the direction of the applied voltage, the bending direction of the rectangular piezoelectric diaphragms 21A and 23A and the bending direction of the rectangular piezoelectric diaphragm 22A shown in FIG. 4, the rectangular piezoelectric diaphragm 21A has a downward convex surface, the rectangular piezoelectric diaphragm 22A has an upward convex surface, and the rectangular piezoelectric diaphragm 23A has a rectangular convex surface as shown in FIG. The convex surface is curved downward, the rectangular piezoelectric diaphragm 24A is curved upward, the rectangular piezoelectric diaphragm 25A is curved downward, and the rectangular piezoelectric diaphragm 26A is curved upward.

  As described above, since an AC voltage is applied to the electrodes 30 and 31, the polarity is reversed after the unit time has elapsed, and accordingly, the rectangular piezoelectric diaphragms 21A, 22A, 23A, 24A, 25A, and 26A are shown in FIG. As shown in FIG.

  Similarly, in the meandering support portions 16B, 19A, and 19B, the bending directions of adjacent rectangular piezoelectric diaphragms are staggered, and the bending direction is reversed each time the polarity of the AC voltage is reversed.

  With such a configuration, the optical reflecting element according to the present embodiment includes adjacent rectangular piezoelectric plates such as the rectangular piezoelectric diaphragm 21A and the rectangular piezoelectric diaphragm in the meandering support portions 16A, 16B, 19A, and 19B. A configuration in which the phase of vibration in 22A is shifted by 180 degrees can be realized. With this configuration, the bending directions of adjacent rectangular piezoelectric diaphragms are staggered, so that the bending angle is added by the number of rectangular piezoelectric diaphragms. As a result, the length of the rectangular piezoelectric diaphragm is increased. Even if this is reduced, bending at a predetermined angle can be obtained in the meandering support portions 16A, 16B, 19A, 19B, and the optical reflecting element 20 can be downsized.

  Further, the phase of the vibration in the rectangular piezoelectric diaphragm 21A and the rectangular piezoelectric diaphragm 22A is shifted by 180 degrees, and the vibration of the rectangular piezoelectric diaphragm 21A is made by making one frequency an integral multiple of the other frequency. And the vibration of the rectangular piezoelectric diaphragm 22A can be resonated, so that the torsion efficiency can be increased.

  In the present embodiment, the rectangular piezoelectric diaphragm 21A has an electrode 31 as a lead wire of the electrode 31 in the rectangular piezoelectric diaphragm 22A, and the rectangular piezoelectric diaphragm 22A has a rectangular piezoelectric diaphragm 23A. The electrode 30 is formed as a lead wire for the electrode 30. When such a lead wire is provided, an insulating layer (for example, the electrode 31) and the piezoelectric layer 33 shown in FIG. It is desirable to provide a structure that is not shown).

  That is, although not shown in FIG. 3, for example, by providing an insulating layer between the piezoelectric layer 33 and the electrode 31 as a lead wire in the rectangular piezoelectric diaphragm 21A, the piezoelectric layer 33 has an electrode 30 and an electrode. Only voltage by 32 is applied, and it can be bent only in a desired direction.

  Further, such a configuration in which the insulating layer is provided between the lead wire and the piezoelectric layer is effective not only in the meandering support portion 16A but also in the meandering support portions 16B, 19A, and 19B.

  The optical reflecting element of the present invention can realize a configuration in which a predetermined driving motion is caused to the optical reflecting portion by applying a small driving voltage to the piezoelectric diaphragm, and is useful in various electric devices such as a laser printer.

The perspective view of the optical reflective element in Embodiment 1 of this invention Part A enlarged perspective view of FIG. B-BB sectional view of FIG. The side view which shows the principle of operation of the optical reflection element in Embodiment 1 of this invention The side view which shows the principle of operation of the optical reflection element in Embodiment 1 of this invention Top view of conventional optical reflector Schematic diagram of a conventional optical reflection element

Explanation of symbols

DESCRIPTION OF SYMBOLS 14 Frame 15 Groove 16A Serpentine support part 17 Frame 18 Groove 19A Serpentine support part 20 Optical reflection part 21A Rectangular piezoelectric diaphragm 22A Rectangular piezoelectric diaphragm 26A Rectangular piezoelectric diaphragm 27A Rectangular piezoelectric diaphragm

Claims (6)

A first frame;
A second frame body separated by a first groove in the first frame body and supported by the first frame body by a first serpentine support portion provided in the first groove; ,
The second frame body is separated by a second groove and is provided with an optical reflecting portion supported by the second frame body by a second meandering support portion provided in the second groove. ,
The first serpentine support portion is provided at least substantially parallel to the first rectangular piezoelectric diaphragm and the first rectangular piezoelectric diaphragm, and at one end of the first rectangular piezoelectric diaphragm. A second rectangular piezoelectric diaphragm connected at one end;
The second meandering support portion is at least provided for a third rectangular piezoelectric diaphragm provided substantially perpendicular to the first rectangular piezoelectric diaphragm and the third rectangular piezoelectric diaphragm. A fourth rectangular piezoelectric diaphragm having one end connected to one end of the third rectangular piezoelectric diaphragm and provided substantially in parallel;
The phase of vibration in the first rectangular piezoelectric diaphragm and the phase of vibration in the second rectangular piezoelectric diaphragm are shifted by 180 degrees,
An optical reflecting element that drives the phase of vibration in the third rectangular piezoelectric diaphragm and the phase of vibration in the fourth rectangular piezoelectric diaphragm by shifting by 180 degrees. The first rectangular piezoelectric diaphragm has first and second electrodes facing each other and a first piezoelectric layer interposed between the first and second electrodes,
The second rectangular piezoelectric diaphragm has third and fourth electrodes facing each other and a second piezoelectric layer interposed between the third and fourth electrodes,
The third rectangular piezoelectric diaphragm has fifth and sixth electrodes facing each other and a third piezoelectric layer interposed between the fifth and sixth electrodes,
The fourth rectangular piezoelectric diaphragm has seventh and eighth electrodes facing each other and a fourth piezoelectric layer interposed between the seventh and eighth electrodes,
The phase of the AC voltage applied to the first electrode in the first rectangular piezoelectric diaphragm and the phase of the AC voltage applied to the third electrode in the second rectangular piezoelectric diaphragm are shifted by 180 degrees,
The phase of the AC voltage applied to the fifth electrode in the third rectangular piezoelectric diaphragm is shifted by 180 degrees from the phase of the AC voltage applied to the seventh electrode in the fourth rectangular piezoelectric diaphragm. Item 2. The optical reflecting element according to Item 1. The optical reflection element according to claim 2, wherein a lead wire to the third electrode in the second rectangular piezoelectric diaphragm is formed on the first rectangular piezoelectric diaphragm. The optical reflection element according to claim 3, wherein a first insulating layer is interposed between the first rectangular piezoelectric diaphragm and a lead line to the third electrode and the piezoelectric layer. The optical reflection element according to any one of claims 2 to 4, wherein a lead line to the seventh electrode in the fourth rectangular piezoelectric diaphragm is formed on the third rectangular piezoelectric diaphragm. The optical reflection element according to claim 5, wherein a second insulating layer is interposed between the lead line to the seventh electrode and the piezoelectric layer in the fourth rectangular diaphragm.