JP2012068451A - Optical scanner and image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scanner capable of preventing rattling of a swing shaft portion without enlargement and an image projection device using the optical scanner.SOLUTION: An optical scanner includes a swing shaft portion, a swing body that is provided to the swing shaft portion and has a reflection surface, a base table that supports the swing shaft portion, and a driving unit that swings the swing shaft portion. To the base table, a first bearing that supports one end of the swing shaft portion and a second bearing that supports the other end of the swing shaft portion are provided. The swing shaft portion has a tapered portion formed into a taper shape at one end. The first bearing is a thrust bearing that engages with the tapered portion, and the second bearing is a radial bearing that comes into contact with an outer peripheral surface of the swing shaft portion.

Description

  The present invention relates to an optical scanner that scans incident light in a predetermined direction, and an image projection apparatus that uses the optical scanner.

  Conventionally, a MEMS mirror is used as a small optical scanner. For example, Patent Document 1 proposes an optical scanner in which a mirror support portion that supports a reflection mirror portion and a frame are provided separately. A bearing is provided in the frame. The mirror support is pivotally supported by this bearing. According to the optical scanner described in Patent Document 1, since the frame body and the mirror support portion are provided separately, when the reflection mirror portion swings, the restoring force due to the twist of the mirror support portion does not work. . As a result, the resonance vibration based on the resonance frequency of the mirror support portion can be sufficiently suppressed.

Japanese Patent Laying-Open No. 2009-244798 (FIGS. 2, 6, etc.)

  In Patent Document 1 described above, the mirror support portion is supported at both ends by a radial bearing. However, when the mirror support portion is supported only by the radial bearing, the mirror support portion can slide in a minute amount in the longitudinal direction. Hereinafter, a slight amount of sliding in the longitudinal direction of the mirror support portion is referred to as “rattle”. When the mirror support part rattles, the reflection mirror part also rattles. Thereby, the position of the light incident on the reflection mirror unit changes. As a result, for example, when the surface shape of the reflection mirror portion varies depending on the location, there arises a problem that the wavefront shape of the reflected light changes. Further, depending on the size of the backlash of the mirror part, the incident light may protrude from the reflection mirror part. That is, if the mirror support is supported only by the radial bearing, the optical characteristics of the reflected light may be deteriorated.

  In order to prevent rattling of the mirror support portion, a combined use of a radial bearing and a thrust bearing is conceivable. Based on this viewpoint, the present inventor created an optical scanner 100 as a reference example, as shown in FIG.

  The optical scanner 100 includes a swing shaft portion 110 as a mirror support portion, a first bearing 120, a second bearing 130, an electromagnetic drive portion 140, and a base base 150 as a frame. In the optical scanner 100, the swing shaft 110 can swing with respect to the pedestal 150 by the first bearing 120 and the second bearing 130. The optical scanner 100 is a so-called moving coil type electromagnetic scanner whose rocking shaft 110 is rocked by an electromagnetic driving unit 140.

  As shown in FIG. 1B, the base 150 has a U-shaped structure when viewed from the X direction. The base 150 may be made of a metal such as aluminum or stainless steel. The base 150 has an L-shaped main portion 151 viewed from the X direction, and a plate-like portion 152 that is fixed to the Y-direction negative side of the main portion 151 with a screw or the like. The main portion 151 is provided with a through hole 153 penetrating along the Y direction. The plate-like portion 152 is provided with a through hole 154 that penetrates along the Y direction. The through hole 153 and the through hole 154 exist at the same position in the X direction and the Z direction.

  The first bearing 120 and the second bearing 130 have the same structure. Therefore, the description of the second bearing 130 is omitted by describing the first bearing 120. The first bearing 120 has a through hole parallel to the Y direction. A radial contact surface 121 that comes into contact with the outer peripheral surface of the swing shaft portion 110 is provided on the inner wall of the through hole. In addition, a thrust contact surface 122 that comes into contact with a stepped portion 112 of the swing shaft 110 described later is provided on the surface of the first bearing 120 on the Y direction negative side. The first bearing 120 and the second bearing 130 are made of, for example, resin. The radial contact surface 121 and the thrust contact surface 122 may be subjected to treatment such as hard chrome / chromium molybdenum plating or fluororesin coating in order to obtain wear resistance and low friction. The first bearing 120 is inserted into the through hole 153, and the second bearing 130 is inserted into the through hole 154.

  The swing shaft portion 110 includes a swing body 111 and step portions 112 and 113. The swing shaft portion 110 is a columnar member that extends parallel to the Y direction. The central axis of the swing shaft portion 110 coincides with the first swing axis L1. The swing shaft 110 is made of a metal material such as stainless steel. A rocking body 111 is provided at a central portion of the rocking shaft portion 110 by removing a predetermined amount of the rocking shaft portion 110 from the Z direction positive side toward the Z direction negative side. A reflective surface 111 a is formed on the surface of the oscillating body 111 by mirror polishing. The first swing axis L1 exists on the reflecting surface 111a. The swing shaft portion 110 is provided with step portions 112 and 113 in which the distance from the first swing axis L1 to the outer peripheral surface of the swing shaft portion 110 changes in the Y direction. The surface on the Y direction positive side of the stepped portion 112 is in contact with the thrust contact surface 122 of the first bearing 120. The surface on the Y direction negative side of the step portion 113 is in contact with the thrust contact surface 132 of the second bearing 130. That is, the first bearing 120 and the second bearing 130 function as both a radial bearing and a thrust bearing at both ends of the swing shaft portion 110.

  The electromagnetic drive unit 140 includes a coil 141 and permanent magnets 142 and 143. The permanent magnets 142 and 143 are provided on the base table 150 between the main portion 151 and the plate-like portion 152. The permanent magnets 142 and 143 are both magnetized in the X direction. The permanent magnets 142 and 143 are arranged in a state of being separated in the X direction so that the different poles face each other. The coil 141 is attached to the opposite side of the rocking body 111 of the rocking shaft 110 so that the wiring pattern is along the direction of the magnetic field generated by the permanent magnets 142 and 143. A current is supplied to the coil 141 from the outside via a wiring not shown in FIG. Due to the interaction between the current flowing through the coil 141 and the magnetic field generated by the permanent magnets 142 and 143, the oscillating body 111 and the oscillating shaft portion 110 oscillate around the first oscillating axis L1.

  In the optical scanner 100 shown in FIG. 1, the first bearing 120 and the second bearing 130 function as both a radial bearing and a thrust bearing. Therefore, sliding of the swing shaft portion 110 in the direction of the first swing axis L1 is prevented. However, like the first bearing 120 and the second bearing 130, bearings that function as both radial bearings and thrust bearings need to have a large support area for the radial bearings. There is a problem that the size of. Therefore, in the configuration of the optical scanner 100 in which both ends of the swing shaft portion 110 are supported by both the radial bearing and the thrust bearing, there is a problem that the size of the optical scanner is increased.

  The present invention relates to an optical scanner in which a frame body and a mirror support portion are provided separately, and an optical scanner capable of preventing the shaking shaft portion from rattling without causing an increase in size, and an image using the optical scanner. An object is to provide a projection device.

  In order to solve the above-described problem, an aspect of the present invention provides a swinging shaft portion that swings about a first swinging axis and that extends in parallel with the first swinging axis, and the swinging shaft portion. An oscillating body having a reflecting surface that reflects incident light, a base pedestal that supports the oscillating shaft, and a first bearing that is provided on the base pedestal and supports one end of the oscillating shaft. A second bearing provided on the base table and supporting the other end of the swing shaft portion; and a drive portion for swinging the swing shaft portion, wherein the swing shaft portion is formed in a tapered shape. The first bearing is a thrust bearing that engages with the tapered portion, and the second bearing is a radial bearing that contacts the outer peripheral surface of the swing shaft portion. This is an optical scanner characterized by that.

  According to this, one end of the oscillating shaft portion having the tapered portion is supported by the first bearing which is a thrust bearing. The other end of the swing shaft portion is supported by a second bearing that is a radial bearing. Therefore, the first bearing and the second bearing need not have the functions of both a radial bearing and a thrust bearing. Therefore, the entire optical scanner is not increased in size. Further, since the first bearing is a thrust bearing and the second bearing is a radial bearing, it is possible to prevent the rocking shaft portion from rattling. Furthermore, since the first bearing is adapted to engage with the tapered portion of the swing shaft portion, the adjustment of the shaft center is facilitated.

  The optical scanner can further include other configurations. That is, you may further have the urging | biasing part which urges | biases the said rocking | fluctuation shaft part in the direction in alignment with the said 1st rocking | fluctuation axis line with respect to the said 1st bearing.

  According to this, the swing shaft portion is biased by the biasing portion in the direction along the first swing axis with respect to the first bearing. Therefore, rattling of the swing shaft portion is further prevented.

  The biasing portion is provided on the swing shaft portion, and a step in which a distance from a central axis of the swing shaft portion to an outer peripheral surface of the swing shaft portion changes in the first swing axis direction. And a first engagement portion that is provided on the second bearing and engages with the step portion in a direction along the swing axis.

  According to this, the urging portion has a step portion provided in the swing shaft portion and an engaging portion provided in the second bearing. Since the step portion comes into contact with the engaging portion of the second bearing, the swing shaft portion can be positioned in a direction parallel to the first swing axis.

  The second bearing is configured separately from the base table, has a second engagement portion that engages with the base table, and the second engagement portion is biased by the base table. Thus, the swing shaft portion may be biased in the direction along the first swing axis with respect to the first bearing via the first engagement portion and the step portion.

  According to this, the 2nd bearing is constituted separately from a base stand. Since the rocking shaft portion does not directly contact the base table around the second bearing, it is possible to reduce resistance when the rocking shaft portion rocks. Moreover, the rocking | fluctuation shaft part can be urged | biased by a base stand because a 2nd engagement part engages with a base stand. This eliminates the need for a special configuration for urging the swing shaft portion.

  The drive unit includes a magnetic field generation unit provided on the base, and a coil provided along the direction of the magnetic field generated by the magnetic field generation unit and attached to the swing shaft unit, The oscillating body and the oscillating shaft may be oscillated around the first oscillating axis by an interaction between a current flowing through the coil and a magnetic field generated by the magnetic field generator.

  According to this, since the restoring force due to the twist of the oscillating shaft portion does not work, an electromagnetic optical scanner in which the resonance vibration based on the resonance frequency is sufficiently suppressed can be obtained.

  The oscillating body includes the reflecting surface and is coupled to a mirror unit that oscillates about a second oscillating axis that is orthogonal to the direction of the first oscillating axis, and both sides of the mirror unit, (2) A pair of torsion beam portions extending in parallel to the swing axis, and one end of the pair of torsion beam portions opposite to the mirror portion, and extending in a direction away from the mirror portion. A plate-like structure in which a main body portion and a mounted portion connected to the other end side of the main body portion and attached to the swing shaft portion are integrally formed of metal, and provided in the main body portion And a piezoelectric drive unit that swings the mirror unit via the main body unit and the pair of torsion beam units by exciting plate waves in the main body unit.

  According to this, it can be said that the oscillating body is a resonance type optical scanner having a structure and a piezoelectric drive unit and oscillating around the second oscillation axis. That is, a two-dimensional optical scanner is obtained that is scanned at a high speed in the swing direction around the second swing axis by the swing body, and is scanned at a low speed in the swing direction around the first swing axis by the swing shaft portion. It is done.

  Further, the attached portion may be attached to the swing shaft portion so as to be positioned closer to the first bearing than the mirror portion.

  According to this, the swinging body is cantilevered at the mounted portion in a state where the mounted portion is positioned closer to the first bearing than the mirror portion. Since the first bearing is a thrust bearing, when the oscillating body and the oscillating shaft are oscillated around the first oscillating axis, the oscillation of the oscillating shaft is smaller than that around the second bearing. Therefore, the vibration transmitted to the rocking body is small, and the scanning blur in the rocking direction around the second rocking axis is small. That is, stable scanning is possible.

  Another aspect of the present invention provides an optical scanner for forming an image by scanning light, a light source for supplying light to the optical scanner, and light scanned by the optical scanner. An image projection apparatus comprising: a light guide section that leads to a projection surface.

  According to this, an image projection apparatus using an optical scanner capable of preventing the rocking shaft portion from rattling without causing an increase in size is provided. Therefore, the image projection apparatus can be downsized.

ADVANTAGE OF THE INVENTION According to this invention, the optical scanner which can prevent the shakiness of a rocking | fluctuation shaft part without causing enlargement, and the image projector using the optical scanner are provided.

1 is an explanatory diagram of an optical scanner 100. FIG. ((A): a view from the perspective of the optical scanner 100, (B): a cross-sectional view taken along the line AA of the optical scanner 100, (C): a plan view of the optical scanner 100) Explanatory drawing of the optical scanner 200 based on 1st Embodiment of this invention. ((A): a view from the perspective of the optical scanner 200, (B): a cross-sectional view taken along the line AA of the optical scanner 200, (C): a plan view of the optical scanner 200) The figure of the cross section which expanded the circumference | surroundings of the 2nd bearing 230 in the optical scanner 200. FIG. The figure explaining the structure of the retinal scanning display 1 based on 1st Embodiment of this invention. Explanatory drawing of the optical scanner 300 based on 2nd Embodiment of this invention. ((A): a view from the perspective of the optical scanner 300, (B): a view taken along the line AA of the optical scanner 300, (C): a plan view of the optical scanner 300) The figure explaining the structure of the retinal scanning display 2 based on 2nd Embodiment of this invention. The figure explaining the structure of the laser projector 4 based on other embodiment of this invention.

  Embodiments reflecting one aspect of the present invention will be described below in detail with reference to the drawings. One aspect of the present invention is not limited to the configuration described below, and various configurations can be employed in the same technical idea. For example, in each configuration described below, a predetermined configuration may be omitted or replaced with another configuration. Moreover, you may make it include another structure.

<First Embodiment>
[Configuration of Optical Scanner 200]
As shown in FIG. 2, the optical scanner 200 includes a swing shaft portion 210, a first bearing 220, a second bearing 230, an electromagnetic drive portion 240, and a base base 250. Similar to the optical scanner 100 described above, the optical scanner 200 is a moving coil type electromagnetic scanner.

  As shown in FIG. 2B, the base 250 has a U-shaped structure when viewed from the X direction. The base table 250 has the same configuration as the base table 150 described above. That is, the base 250 has a main part 251 and a plate-like part 252. The main portion 251 is provided with a through hole 253 penetrating along the Y direction, and the plate-like portion 252 is provided with a through hole 254 penetrating along the Y direction. The through hole 253 and the through hole 254 exist at the same position in the X direction and the Z direction. Note that the inner diameter of the through hole 254 is sufficiently larger than the outer diameter of the swing shaft portion 210. Since the swing shaft part 210 is supported by the second bearing 230, the outer peripheral surface of the swing shaft part 210 does not contact the through hole 254. Therefore, when the swinging shaft part 210 swings, resistance due to the contact between the outer peripheral surface of the swinging shaft part 210 and the inner wall of the through hole 254 does not occur.

  Whereas the first bearing 120 described above has a through hole, the first bearing 220 has a blind hole dug down from the surface on the Y direction positive side toward the Y direction negative side. The blind hole has the same diameter up to the center of the first bearing 220 in the Y direction, and the tip of the blind hole is constricted in a mortar shape. The surface of the portion constricted in a mortar shape is a taper contact surface 221. A tapered portion 212 of the swing shaft portion 210 to be described later is held in contact with the tapered contact surface 221. The first bearing 220 is made of, for example, resin. The taper contact surface 221 may be subjected to a treatment such as hard chrome / chromium molybdenum plating or fluorine resin coating.

  As shown in FIGS. 2B and 3, the second bearing 230 is configured separately from the plate-like portion 252 of the base table 250. The second bearing 230 has a radial contact surface 231, a thrust contact surface 232 as a first engagement portion, and a base base engagement portion 233 as a second engagement portion. The second bearing 230 has a cylindrical configuration having a through hole penetrating in the Y direction. The inner diameter of the through hole is larger than the outer diameter of the swing shaft portion 210 so that the swing shaft portion 210 can be supported. A radial contact surface 231 that contacts the outer peripheral surface of the swing shaft portion 210 is provided on the inner wall of the through hole. A thrust contact surface 232 that comes into contact with a step portion 213 of the swing shaft portion 210 to be described later is provided on the surface on the Y direction positive side of the second bearing 230. Further, the outer diameter of the second bearing 230 is larger than the inner diameter of the through hole 254 of the plate-like portion 252. The base bearing engaging portion 233 whose outer diameter is smaller than the inner diameter of the through hole 254 is provided at the Y-direction negative end of the second bearing 230. The second bearing 230 is held between the plate-like portion 252 of the base base 250 and the stepped portion 213 of the swing shaft portion 210 by the base base engaging portion 233 engaging with the through hole 254. And the 2nd bearing 230 is urged | biased to the Y direction positive | positive side using the spring property of the plate-shaped part 252. FIG. The second bearing 230 biased to the Y direction positive side biases the stepped portion 213 to the Y direction positive side by the thrust contact surface 232. As a result, the swing shaft portion 210 is biased in the direction along the first swing axis L1 with respect to the first bearing 220. The second bearing 230 is made of resin, for example. Further, the radial contact surface 231, the thrust contact surface 232, and the base base engaging portion 233 are treated with hard chrome / chromium molybdenum plating or fluororesin coating in order to obtain wear resistance and low friction. May be applied.

  The swing shaft portion 210 has a swing body 211, a tapered portion 212, and a step portion 213. The swing shaft part 210 is a columnar member extending in parallel to the Y direction. The central axis of the swing shaft part 210 coincides with the first swing axis L1. The swing shaft part 210 is made of a metal material such as stainless steel. As in the case of the swing shaft 110, a swing body 211 is provided at the central portion of the swing shaft 210. On the surface of the oscillating body 211, a reflecting surface 211a is formed by mirror polishing. In addition, the reflective surface 211a may be formed by affixing another member by which the mirror surface process was carried out. The first swing axis L1 exists on the reflecting surface 211a. A tapered portion 212 having a diameter that decreases along the Y direction (that is, a tapered shape) is formed at the end of the swing shaft portion on the Y direction negative side. The surface of the tapered portion 212 is held in contact with the tapered contact surface 221 of the first bearing 220. The swing shaft portion 210 is provided with a step portion 213 in which the distance from the first swing axis L1 to the outer peripheral surface of the swing shaft portion 210 changes in the Y direction. The surface on the Y direction negative side of the step portion 213 is in contact with the thrust contact surface 232 of the second bearing 230. By this contact, the swing shaft portion 210 is positioned in the Y direction. Further, the step portion 213 is biased to the Y direction positive side by the plate-like portion 252 via the second bearing 230. Therefore, the tapered portion 212 is pressed against the tapered contact surface 221. As a result, rattling of the rocking shaft portion 210 is prevented and adjustment of the axis of the rocking shaft portion 120 is facilitated. Further, since the oscillating shaft portion 210 is provided with the tapered portion 212, the size of the optical scanner 200 in the Y direction can be reduced as compared with the optical scanner 100 using the oscillating shaft portion 110. .

  The electromagnetic drive unit 240 includes a coil 241 and a permanent magnet 242 as a magnetic field generation unit. The permanent magnet 242 is provided on the base table 150 so as to face the coil 241 while being magnetized in the X direction. The coil 241 is attached to the opposite side of the swinging member 211 of the swinging shaft part 210 so that the wiring pattern follows the direction of the magnetic field generated by the permanent magnet 242. The coil 241 is configured by attaching a thin film planar coil to a flat support member made of a nonmagnetic material such as synthetic resin. The thin planar coil is, for example, a flexible printed circuit board (FPC) in which an adhesive layer is formed on a film-like insulator (base film), and a spiral conductive pattern is further formed thereon with a conductive foil. . Note that the coil 241 may have a configuration in which a conductive pattern is directly formed on the support member instead of a configuration in which the FPC is attached to the support member. The coil 241 may be configured by a coil such as a wound coil. In place of the permanent magnet 242, an electromagnet may be used as the magnetic field generator.

[Configuration of Retina Scanning Display 1]
The optical scanner 200 described above can be used in the retinal scanning display 1 as a configuration for scanning light to form an image. FIG. 4 is a diagram for explaining the overall configuration of the retinal scanning display 1. The retinal scanning display 1 is a device that allows an observer to visually recognize a virtual image by projecting an image on the retina 54 using a light beam incident on the pupil 52 of the observer.

  The retinal scanning display 1 includes a control unit 1a and a head display unit 1b. The control unit 1a and the head display unit 1b are configured separately. The control unit 1a is attached to a user's waist, for example. The head display unit 1b is connected to the control unit 1a by a signal line capable of transmitting electrical and optical signals. The head display unit 1b is mounted on the user's head using, for example, a spectacle-shaped mounting tool as disclosed in, for example, US Patent Application Publication No. 2010/0073262. Of course, the control unit 1a and the head display unit 1b may be configured integrally.

  The control unit 1 a includes a video signal processing circuit 3, a light source unit 30, and an optical multiplexing unit 40. The video signal processing circuit 3 generates a B signal, a G signal, an R signal, a horizontal synchronization signal, and a vertical synchronization signal for forming an image based on a video signal supplied from the outside.

  The light source unit 30 includes a B laser driver 31, a G laser driver 32, an R laser driver 33, a B laser 34, a G laser 35, and an R laser 36. The B laser driver 31 drives the B laser 34 so as to generate a blue light beam having an intensity corresponding to the B signal from the video signal processing circuit 3. The G laser driver 32 drives the G laser 35 so as to generate a green light beam having an intensity corresponding to the G signal from the video signal processing circuit 3. The R laser driver 33 drives the R laser 36 so as to generate a red light beam having an intensity corresponding to the R signal from the video signal processing circuit 3. The B laser 34, the G laser 35, and the R laser 36 can be configured using, for example, a semiconductor laser or a solid-state laser with a harmonic generation mechanism.

  The optical combining unit 40 includes collimating optical systems 41, 42, and 43, dichroic mirrors 44, 45, and 46 for combining the collimated laser light, and condensing optics for condensing the combined laser light. A system 47. The blue laser light emitted from the B laser 34 is collimated by the collimating optical system 41. The collimated blue laser light is incident on the dichroic mirror 44. The green laser light emitted from the G laser 35 is collimated by the collimating optical system 42. The collimated green laser light is incident on the dichroic mirror 45. The red laser light emitted from the R laser 36 is collimated by the collimating optical system 43. The collimated red laser light is incident on the dichroic mirror 46. The blue, green, and red laser beams respectively incident on the dichroic mirrors 44, 45, and 46 are reflected or transmitted in a wavelength selective manner and are combined as one light beam, and reach the condensing optical system 47. The combined laser light is condensed by the condensing optical system 47 and guided to the head display unit 1b via an optical fiber or the like.

  The head display unit 1b includes a collimating optical system 20, a horizontal scanning driver 23, a horizontal scanning scanner 10, a relay optical system 24, a vertical scanning driver 26, an optical scanner 200, and an eyepiece optical system 27.

  The collimating optical system 20 converts the laser light guided from the control unit 1a through an optical fiber or the like into parallel light. The laser light converted into parallel light enters the horizontal scanning scanner 10.

  The horizontal scanning scanner 10 scans the laser light from the collimating optical system 20 in the horizontal direction (for example, the left-right direction with respect to the eyes of the observer). Specifically, the horizontal scanning driver 23 controls the swinging state of the horizontal scanning scanner 10 according to the horizontal synchronization signal from the video signal processing circuit 3. The horizontally scanned laser light enters the relay optical system 24. As the horizontal scanning scanner 10, for example, an optical scanner driven by a piezoelectric element, and a resonance type optical scanner using a resonance phenomenon of a structure constituting the outer shape of the optical scanner can be used. (See Kaikai 2006-293116).

  The relay optical system 24 includes lens systems 24a and 24b having a positive refractive power. The lens system 24 a is arranged at a position away from the focal length of the lens system 24 a from the horizontal scanning scanner 10. Accordingly, the horizontally scanned laser light is refracted by the lens system 24a so that the optical axes thereof are parallel to each other. Further, the horizontally scanned laser light is converted into parallel light by the collimating optical system 20 and is therefore converted as focused light. In FIG. 4, the optical axis of the laser light is indicated by a dotted line, and the light beam of the laser light passing through the centers (= optical axes) of the relay optical system 24 and the eyepiece optical system 27 is indicated by a solid line. The lens system 24b is arranged at a position away from the lens system 24a by the total distance of the focal length of the lens system 24a and the focal length of the lens system 24b. Accordingly, the laser light that has passed through the lens system 24 a is refracted by the lens system 24 b so that the optical axes of the laser light are focused on the reflecting surface 211 a of the optical scanner 200. The laser light converted as the focused light when passing through the lens system 24a is converted into parallel light again by the lens system 24b. In other words, the relay optical system 24 functions to transfer the optical pupil (= laser light incident point) formed in the horizontal scanning scanner 10 onto the reflection surface 211 a of the optical scanner 200.

  The optical scanner 200 scans the laser beam from the relay optical system 24 in the vertical direction (for example, the vertical direction with respect to the observer's eyes). The vertical scanning driver 26 controls the swing state of the optical scanner 200 according to the vertical synchronization signal from the video signal processing circuit 3. Here, since the laser beam is scanned in the horizontal direction by the horizontal scanning scanner 10, it becomes image light scanned two-dimensionally by the optical scanner 200. The two-dimensionally scanned image light enters the eyepiece optical system 27.

  The eyepiece optical system 27 includes lens systems 27a and 27b having a positive refractive power. The eyepiece optical system 27 functions to transfer the optical pupil formed in the optical scanner 200 to the pupil 52 of the observer's eye, like the relay optical system 24. The image light emitted from the eyepiece optical system 27 passes through the pupil 52 of the observer's eye and forms an image on the retina 54. Therefore, the observer visually recognizes the image.

<Second Embodiment>
In the optical scanner 200 according to the first embodiment, the oscillating body 211 is a part of the oscillating shaft portion 210. A reflection surface 211 a is provided on the surface of the oscillator 211. In other words, the optical scanner 200 is a one-dimensional optical scanner that scans incident light in the X direction by rotating the rocking shaft portion 210 around the rocking axis L1. However, the present invention is not limited to this. The present invention can also have a side surface as a two-dimensional optical scanner by making the oscillator a different configuration. Hereinafter, the optical scanner 300 which is a two-dimensional optical scanner will be described with reference to FIG. In addition, in the optical scanner 300, about the same structure as the above-mentioned optical scanner 200, description is abbreviate | omitted by employ | adopting the same figure number.

[Configuration of Optical Scanner 300]
The optical scanner 300 is different from the optical scanner 200 described above in the configuration of the swing shaft portion 310. Like the swinging shaft part 210, the swinging shaft part 310 is a columnar member that extends parallel to the Y direction. The swing shaft portion 310 includes a swing body 311, a tapered portion 312, and a step portion 313. The tapered portion 312 and the step portion 313 have the same configuration as the tapered portion 212 and the step portion 213 in the optical scanner 200. On the other hand, unlike the oscillating body 211 of the optical scanner 200, the oscillating body 311 of the optical scanner 300 is a flat metal member that is configured separately from the oscillating shaft portion 310. The oscillating body 311 is provided with a piezoelectric drive unit 311d described later. The piezoelectric driving unit 311 d periodically expands and contracts at the resonance frequency of the structure 311, thereby exciting plate wave vibration in the structure 311. By transmitting the plate wave vibration to the structure 311, the reflecting surface 311 a included in the structure 311 swings about the second swing axis L 2.

  The oscillating body 311 includes a mirror portion 311a, torsion beam portions 311b1 and 311b2, a main body portion 311c, and a piezoelectric drive portion 311d. The rocking body 311 is formed symmetrically with respect to the first rocking axis L1. The oscillating body 311 is manufactured by forming each of the above-described structures on a metal plate such as stainless steel or titanium having a thickness of several tens to several hundreds of μm using a removal process such as an etching process or a press process. . However, the oscillator 311 may be formed of a non-metallic material such as a silicon wafer. In this case, a conductive layer such as a metal thin film is preferably provided on the surface of the nonmetallic material.

  The mirror portion 311a swings at a predetermined resonance frequency around the second swing axis L2 parallel to the X direction. The mirror part 311a is formed in a substantially circular shape when viewed from the Z direction. However, the mirror part 311a may have another shape such as a quadrangle or a polygon. A reflective surface 311a1 is provided on the surface on the positive side in the Z direction of the mirror portion 311a so as to reflect incident light. The reflective surface 311a1 is formed by mirror polishing the surface on the positive side in the Z direction of the mirror portion 311a. However, instead of mirror polishing, a metal thin film having a high reflectance with respect to visible light such as aluminum or silver is provided on the surface on the positive side in the Z direction of the reflective surface 311a by vapor deposition, sputtering, etc. A surface 311a1 may be formed.

  The torsion beam portions 311b1 and 311b2 are connected to both sides of the mirror portion 311a and extend parallel to the second swing axis L2. Specifically, the torsion beam portion 311b1 extends from the mirror portion 311a to the X direction positive side parallel to the second swing axis L2, and the torsion beam portion 311b2 is parallel to the second swing axis L2 from the mirror portion 311a. To the X direction negative side.

  The main body 311c includes ear portions 311c1 and 311c2 and a mounted portion 311c3. The end portion on the X direction positive side of the torsion beam portion 311b1 is connected to the ear portion 311c1. The end portion on the X direction negative side of the torsion beam portion 311b2 is connected to the ear portion 311c2. The ear portion 311c1 is connected to the end portion on the positive side in the X direction of the main body portion 311c on the Y direction negative side side of the main body portion 311c. The ear portion 311c2 is connected to the end portion on the negative side in the X direction of the main body portion 311c on the side on the negative side in the Y direction of the main body portion 311c. The main body portion 311c extends from the connection position between the ear portions 311c1 and 311c2 and the torsion beam portions 311b1 and 311b2b in a direction away from the mirror portion 311a, that is, the Y direction positive side. A mounted portion 311c3 is provided at the end of the main body portion 311c on the Y direction positive side.

  The attached portion 311c3 is fixed to the swinging shaft portion 310 in a state where the piezoelectric drive portion 311d is provided on the main body portion 311c. In this fixing, the mounted portion 311c3 is set so that the second swing axis L2 is orthogonal to the first swing axis L1, in other words, the second swing axis L2 is parallel to the X direction. And the rocking shaft portion 310 are fixed. Further, the fixed position between the attached portion 311 c 3 and the swing shaft portion 310 is adjacent to the first bearing 220. Since the tapered portion 312 of the swing shaft portion 310 is pressed against the taper contact surface 221, the vibration of the swing shaft portion 310 around the first bearing 220 is caused by the swing shaft portion 310 around the second bearing 230. Is less than the vibration. Therefore, the attached portion 311c3 is positioned closer to the first bearing 220 than the mirror portion 311a, so that the amount of vibration transmitted from the swing shaft portion 310 to the swing body 311 can be reduced. As a result, the swing about the second swing axis L2 is stabilized. Here, the first swing axis L1 exists on the reflection surface 311a in a state where the main body 311c is fixed to the swing shaft 310. Therefore, the portion of the rocking shaft portion 310 located on the Z direction negative side of the rocking body 311 is closer to the Z direction negative side than the first rocking axis L1 in order to secure a space in which the rocking body 311 can vibrate. A predetermined amount is deleted.

  The piezoelectric drive unit 311d is provided on the surface on the positive side in the Z direction of the main body 311c at the center position of the main body 311c. For example, the piezoelectric drive unit 311d is made of 0.2 μm to 0.6 μm of gold, platinum, or the like as an electrode layer on both sides of a piezoelectric material such as lead zirconate titanate formed into a flat plate having a thickness of 30 μm to 100 μm. It is formed by stacking. The piezoelectric drive unit 311d and the main body unit 311c are bonded with a conductive adhesive. This conductive adhesive is, for example, one in which a metal filler composed of silver, gold, copper, etc. is dispersed in a base made of a thermosetting epoxy resin, acrylic resin, silicon resin or the like. It is. First, the piezoelectric drive unit 311d is placed on the conductive adhesive applied to the main body 311c. In this state, the conductive adhesive is thermally cured, so that the piezoelectric drive unit 311d and the main body 311c are bonded. Since the oscillating body 311 is formed of a metal plate, an AC voltage corresponding to the resonance frequency of the oscillating body 311 is applied between the oscillating body 311 and the Z-direction positive electrode layer of the piezoelectric drive unit 311d. A plate wave is excited in the main body 311c. The plate wave is transmitted to the mirror part 311a through the main body part 311c and the torsion beam parts 311b1 and 311b2, so that the mirror part 311a swings at a predetermined resonance frequency.

[Configuration of Retina Scanning Display 2]
The optical scanner 300 described above can be used in the retinal scanning display 2 as a configuration for scanning light to form an image. In the retinal scanning display 1 according to the first embodiment, the horizontal scanning scanner 10 that scans light in the horizontal direction and the optical scanner 200 that scans light in the vertical direction are separate structures. However, since the optical scanner 300 can perform two-dimensional scanning, the retinal scanning display 2 can achieve horizontal scanning and vertical scanning only by the optical scanner 300. Hereinafter, the configuration of the retinal scanning display 2 will be described with reference to FIG.

  The retinal scanning display 2 includes a control unit 2a and a head display unit 2b. The configuration of the control unit 2a is the same as that of the control unit 1a in the retinal scanning display 2. For this reason, only the head display unit 2b will be described. Similarly to the head display unit 1b, the head display unit 2b is also mounted on the user's head using a spectacle-shaped mounting tool or the like.

  The head display unit 2 b includes a collimating optical system 20, a horizontal scanning driver 23, a vertical scanning driver 26, an optical scanner 300, and an eyepiece optical system 27. In addition, the same drawing number is provided about the structure similar to the structure contained in the head display unit 1b in 1st Embodiment. The collimating optical system 20 collimates the laser light guided from the control unit 2a and enters the reflecting surface 311a1 of the optical scanner 300. The optical scanner 300 is controlled in its oscillation state by the horizontal scanning driver 23 and the vertical scanning driver 26, and converts the incident laser light into image light that has been two-dimensionally scanned. Specifically, the horizontal scanning driver 23 is electrically connected to the main body 311c and the piezoelectric driving unit 311d of the oscillator 311. The horizontal scanning driver 23 swings the mirror unit 311a in the horizontal direction by supplying a driving current generated based on the horizontal synchronizing signal from the video signal processing circuit 3 to the piezoelectric driving unit 311d. The vertical scanning driver 26 is electrically connected to the coil 241. The vertical scanning driver 26 swings the swinging shaft portion 310 in the vertical direction by supplying a drive current generated based on the vertical synchronization signal from the video signal processing circuit 3 to the coil 241. The two-dimensionally scanned image light passes through the pupil 52 of the observer's eye by the eyepiece optical system 27 and forms an image on the retina 54.

<Modification>
The present invention is not limited to the embodiments described so far, and various modifications and changes can be made without departing from the spirit of the present invention. An example is described below.

  In the above-described embodiment, the stepped portion 213 is biased to the Y direction positive side by the plate-like portion 252 via the second bearing 230. However, the configuration for pressing the tapered portion 212 against the tapered contact surface 221 may be achieved by other means. For example, in the base stand 250, a leaf spring is provided on the negative surface of the plate-like portion 252 in the Y direction. The leaf spring may contact the second bearing 230 to exert a biasing force on the positive side in the Y direction with respect to the swing shaft portion 210.

  In the above-described embodiment, the optical scanner 200 is a so-called moving coil type optical scanner in which the coil 241 is provided on the swing shaft portion 210 and the permanent magnet 242 is provided on the base base 250. However, the optical scanner 200 may be configured as a so-called moving magnet type optical scanner in which the permanent magnet 242 is provided in the swing shaft portion 210 and the coil 241 is provided in the base table 250. Of course, the same applies to the optical scanner 300.

  In the above-described embodiment, in the retinal scanning display 2, the laser beam is scanned in the vertical direction after being scanned in the horizontal direction. However, for example, by replacing the horizontal scanner 10 and the optical scanner 200, the laser beam may be scanned in the horizontal direction after being scanned in the vertical direction. Alternatively, the horizontal direction may be defined in the up-down direction with respect to the observer's eye, and the vertical direction may be defined in the left-right direction with respect to the observer's eye.

  In the above-described embodiment, the optical scanner 300 is used for the retinal scanning display 2. However, the optical scanner 300 may be used for any other purpose. As an example, as shown in FIG. 7, the optical scanner 300 may be used in a laser projector 4 that forms an image of scanned laser light on a projection surface. The laser projector 4 is different from the retinal scanning display 2 in an optical system subsequent to the optical scanner 300. Therefore, the description regarding the configuration common to the retinal scanning display 2 in the laser projector 4 is omitted by adopting the same figure number. The imaging optical system 28 is a lens system having a positive refractive power. The imaging optical system 28 focuses the collimated laser beam from the optical scanner 300 to form an image on a projection surface such as a screen. It is desirable that the imaging optical system 28 has a predetermined focus adjustment function in order to form an image on a projection surface at an arbitrary distance. Alternatively, if the beam diameter of the laser beam is sufficiently small, the imaging optical system 28 may be omitted. In this case, the parallel laser beam from the optical scanner 300 directly images the projection surface. Will be drawn. In this case, the light guide does not exert an optical action on the laser light. Of course, the configuration of the retinal scanning display 1 may be used as a laser projector.

DESCRIPTION OF SYMBOLS 1, 2 Retina scanning display 1a Control unit 1b Head display unit 3 Video signal processing circuit 4 Laser projector 100,200,300 Optical scanner 20,41,42,43 Collimating optical system 23 Horizontal scanning driver 24 Relay optical system 24a, 24b 27a, 27b Lens system 25 Vertical scanning scanner 26 Vertical scanning driver 27 Eyepiece optical system 28 Imaging optical system 30 Light source 31 B laser driver 32 G laser driver 33 B laser driver 34 B laser 35 G laser 36 R laser 40 Optical multiplexing Units 44, 45, 46 Dichroic mirror 47 Condensing optical system 52 Observer pupil 54 Retina 110, 210, 310 of observer Oscillating shafts 111, 211, 311 Oscillators 111a, 211a, 311a1 Reflecting surfaces 112, 113, 213,313 Step part 1 0, 220 First bearing 121, 131, 231 Radial contact surface 122, 132, 232 Thrust contact surface 233 Base base engaging portion 130, 230 Second bearing 140 Electromagnetic drive unit 141, 241 Coil 142, 143, 242 Permanent magnet 150 , 250 Base bases 151, 251 Main parts 152, 252 Plate-like parts 153, 154, 253, 254 Through holes 212, 312 Tapered part 221 Tapered contact surface 311a Mirror part 311b1, 311b2 Twisted beam part 311c Body part 311c1, 311c2 Ear Part 311c3 Mounted part 311d Piezoelectric drive part

Claims (8)

A swing shaft that swings about the first swing axis and extends parallel to the first swing axis;
An oscillating body provided on the oscillating shaft and having a reflecting surface for reflecting incident light;
A base stand for supporting the swing shaft portion;
A first bearing provided on the base table and supporting one end of the pivot shaft;
A second bearing provided on the base table and supporting the other end of the swing shaft;
A drive unit that rocks the rocking shaft,
The swing shaft portion has a tapered portion formed in a tapered shape at the one end,
The first bearing is a thrust bearing that engages with the tapered portion;
The second bearing is a radial bearing that comes into contact with an outer peripheral surface of the swing shaft portion.
An optical scanner characterized by that. An urging portion for urging the oscillating shaft portion with respect to the first bearing in a direction along the first oscillating axis;
The optical scanner according to claim 1. The biasing part is
A step portion provided in the swing shaft portion, wherein a distance from a central axis of the swing shaft portion to an outer peripheral surface of the swing shaft portion changes in the first swing axis direction;
A first engagement portion provided on the second bearing and engaged with the step portion in a direction along the swing axis;
The optical scanner according to claim 2. The second bearing is
It is configured separately from the base table,
A second engaging portion that engages with the base base;
When the second engagement portion is urged by the base, the first swing portion is moved with respect to the first bearing via the first engagement portion and the step portion. Urging in the direction along the axis,
The optical scanner according to claim 3. The drive unit is
A magnetic field generator provided on the base table;
A coil provided along the direction of the magnetic field generated by the magnetic field generator, and attached to the swing shaft;
Oscillating the oscillating body and the oscillating shaft portion around the first oscillating axis by the interaction between the current flowing through the coil and the magnetic field generated by the magnetic field generating portion;
The optical scanner according to claim 1. The oscillator is
A mirror portion including the reflecting surface and swinging about a second swing axis perpendicular to the direction of the first swing axis;
A pair of torsion beam portions connected to both sides of the mirror portion and extending parallel to the second swing axis;
One end of the pair of torsion beam portions is connected to the opposite end of the mirror portion, and a main body portion extending in a direction away from the mirror portion,
An attached portion connected to the other end side of the main body portion and attached to the swing shaft portion;
A plate-shaped structure integrally formed of metal,
A piezoelectric drive unit that is provided in the main body unit and excites a plate wave in the main body unit to swing the mirror unit via the main body unit and the pair of torsion beam units;
An optical scanner according to any one of claims 1 to 5. The attached portion is attached to the swing shaft portion so as to be positioned closer to the first bearing than the mirror portion.
The optical scanner according to claim 6. An optical scanner according to any one of claims 1 to 7, for forming an image by scanning light;
A light source for supplying light to the optical scanner;
An image projection apparatus comprising: a light guide unit that guides light scanned by the optical scanner to a projection surface.

Images