Optical scanning device

Abstract

To provide an optical scanner that can widen an eye-box with a simple structure and also can widen an angle of field.SOLUTION: The optical scanner includes: a light source for emitting a laser beam; a mirror device having a movable mirror which rocks around at least one axis, the mirror device reflecting the laser beam from the light source by the movable mirror and changing the direction of the laser beam; and a light collection optical system for collecting the laser beam of which direction has been changed by the mirror device. The light collection optical system includes: a half mirror with a recessed surface; and a diffusion plate with a plurality of micro mirrors for diffusing the laser beam having passed through the half mirror from the recessed surface side.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The technology of the present disclosure relates to an optical scanning device.

Background Art

[0002] In recent years, AR (Augmented Reality) glasses that superimpose virtual images, various information, etc. on the actual viewed scene have been put into practical use. AR glasses are also called smart glasses, head-mounted displays (HMDs), AR glasses, etc.

[0003] Some AR glasses adopt a method of directly scanning the retina of the user's eye by deflecting the laser light emitted from a light source with a movable mirror (also referred to as a MEMS mirror) composed of MEMS (Micro Electro Mechanical Systems). Such a method is called a retina scanning method. In AR glasses using the retina scanning method, the laser light deflected by the movable mirror is condensed by a condensing optical system onto the pupil of the user's eye and scanned onto the retina. Since the retina scanning method does not depend on the focusing function of the eye's lens, the user can clearly see the image projected onto the retina even if they are nearsighted, farsighted, or presbyopic. In addition, AR glasses using the retina scanning method have high energy efficiency and can be driven for a long time.

[0004] On the other hand, in AR glasses using the retina scanning method, if the position of the focus point of the laser light by the condensing optical system does not coincide with the position of the pupil, the image cannot be seen. That is, there is a problem that when the user moves their eyes and the position of the pupil deviates from the focus point, the image cannot be seen. This problem is known as a narrow range within which the eyes can be moved to view the image clearly, that is, a narrow eyebox.

[0005] In this way, in the case of the retinal scanning type AR glasses, expanding the eyebox has been an issue. In Patent Document 1, a technique for expanding the eyebox by replicating the laser light deflected by a movable mirror with a prism or a light guide plate is known. Also, in Non-Patent Document 1, a technique for expanding the eyebox by condensing the laser light on the position of the pupil by a mirror while tracking the position of the pupil by eye tracking is known.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Non-Patent Documents

[0007]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, since the technologies described in Patent Document 1 and Non-Patent Document 1 have a complicated configuration for expanding the eye box, a technology that enables the expansion of the eye box with a simpler configuration is desired. Furthermore, a technology that enables the expansion of the eye box and the expansion of the viewing angle is desired.

[0009] An object of the technology of the present disclosure is to provide an optical scanning device that can expand the eye box with a simple configuration and can expand the viewing angle.

Means for Solving the Problems

[0010] To achieve the above object, the optical scanning device of the present disclosure includes a light source that emits laser light, a mirror device having a movable mirror that swings around at least one axis, and deflects the laser light emitted from the light source by reflection with the movable mirror, and a condensing optical system that condenses the laser light deflected by the mirror device. The condensing optical system includes a half mirror having a concave surface, and a diffusing plate formed with a plurality of micromirrors that diffuse the laser light transmitted through the half mirror from the concave surface side.

[0011] The condensing optical system preferably condenses the laser light deflected by the mirror device at the center of the eyeball.

[0012] The concave surface is preferably an elliptical surface, the swing axis of the movable mirror is located at one focus of the elliptical surface, and the center of the eyeball is located at the other focus.

[0013] The diffusing plate preferably diffuses the laser light transmitted through the half mirror from the concave surface side in a direction other than the specular reflection direction.

[0014] The half mirror and the diffusing plate are preferably formed of materials having the same refractive index.

[0015] The movable mirror is preferably configured to be swingable around a first axis and a second axis that are orthogonal to each other.

Effects of the Invention

[0016] According to the technology of the present disclosure, it is possible to provide an optical scanning device that can expand an eyeglass case with a simple configuration and expand a viewing angle.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments according to the technology of the present disclosure will be described in detail with reference to the drawings. As an example, in the following embodiments, a form in which an optical scanning device according to the technology of the present disclosure is applied to AR glasses will be described.

[0019] Figure 1 shows the configuration of the AR glasses 10 according to the present embodiment. As shown in Figure 1, the AR glasses 10 are composed of a frame 11, two lenses 12, two temples 13, a module 14, and a condensing optical system 15. The two lenses 12 are held by the frame 11. The two temples 13 are respectively connected to the ends of the frame 11 via hinges (not shown).

[0020] The module 14 is provided on one of the two temples 13. Also, a condensing optical system 15 is provided on the lens 12 on the temple 13 side where the module 14 is provided among the two lenses 12. In the present embodiment, the module 14 is provided on the right temple 13, and the condensing optical system 15 is provided on the right lens 12. Note that the module 14 may be provided on both of the two temples 13, and the condensing optical system 15 may be provided on both of the two lenses 12.

[0021] The module 14 emits the laser light L modulated according to the image signal toward the condensing optical system 15. The condensing optical system 15 reflects a part of the laser light L incident from the module 14 and condenses it on the center of the eyeball of the user wearing the AR glasses 10. The symbol P indicates the condensing point of the laser light L by the condensing optical system 15. Although it will be described in detail later, the condensing optical system 15 is configured to reflect a part of the laser light L incident from the module 14 and diffuse a part of it.

[0022] Figure 2 shows the configuration of the module 14 and the condensing optical system 15. As shown in Figure 2, the module 14 includes a control device 20, a MEMS (Micro Electro Mechanical Systems) driver 22, a light emitting device 24, a multiplexing optical system 26, a collimator 28, and a MEMS mirror 30. The MEMS mirror 30 is an example of the "mirror device" according to the technology of the present disclosure.

[0023] The light emitting device 24 includes a laser driver 25 and a laser light source 27. The laser driver 25 of the present embodiment drives the laser light source 27 based on the intensity modulation signal supplied from the control device 20, and outputs laser light L for forming an image from the laser light source 27. The laser light source 27 outputs, for example, three-color laser light L of R (Red), G (Green), and B (Blue). The laser light source 27 is an example of the "light source" according to the technology of the present disclosure.

[0024] The laser light L output from the laser light source 27 is combined by the wavelength multiplexing optical system 26, and then irradiated to the MEMS mirror 30 through the collimator 28. The laser light L irradiated to the MEMS mirror 30 is reflected by the MEMS mirror 30 toward the condenser optical system 15.

[0025] The MEMS driver 22 drives the MEMS mirror 30 based on the control from the control device 20. In the MEMS mirror 30, a mirror part 40 (see FIG. 3) that reflects the laser light L swings independently about each of two mutually orthogonal axes as central axes. In the present embodiment, when the mirror part 40 swings based on the drive signal, the laser light L is scanned in a state of drawing a Lissajous curve in the condenser optical system 15. The Lissajous curve is a curve determined by the swing frequency around the first axis, the swing frequency around the second axis, and their phase difference. The mirror part 40 is an example of the "movable mirror" according to the technology of the present disclosure. The MEMS mirror 30 deflects the laser light L by reflecting it with the mirror part 40. Note that deflection means changing the traveling direction of the laser light L.

[0026] The control device 20 of the present embodiment includes an FPGA (Field Programmable Gate Array) 20A and a memory 20B. The memory 20B is, for example, a volatile memory, and stores various information such as an image signal representing an image projected onto the condenser optical system 15. The memory 20B stores, for example, an image signal input from the outside of the AR glass 10.

[0027] The light collecting optical system 15 is composed of a half mirror 16 and a diffuser plate 17. Laser light L deflected by the MEMS mirror 30 is incident on the half mirror 16. The diffuser plate 17 is joined to the surface on the side opposite to the surface on which the laser light L of the half mirror 16 is incident.

[0028] A concave surface 16A for specularly reflecting a part of the laser light L incident from the MEMS mirror 30 is formed on the half mirror 16. The half mirror 16 specularly reflects a part of the laser light L and transmits a part of it. The laser light L transmitted through the half mirror 16 is incident on the diffuser plate 17. In FIG. 2, illustration of the laser light L transmitted through the half mirror 16 is omitted.

[0029] In the present embodiment, the concave surface 16A is an elliptical surface. More specifically, the concave surface 16A is a part of the surface of a rotational ellipsoid formed by rotating an ellipse about an axis passing through its two foci. That is, the concave surface 16A is an aspherical elliptical surface. When the light output from one of the foci is specularly reflected by the concave surface 16A, it always reaches the other focus.

[0030] The AR glass 10 is configured such that the swing axis of the MEMS mirror 30 is located at one focus of the concave surface 16A and the center of the user's eyeball EB is located at the other focus. Due to this geometric relationship, a part of the laser light L incident from the MEMS mirror 30 on the light collecting optical system 15 is reflected by the concave surface 16A of the half mirror 16 and converges on the center of the eyeball EB.

[0031] A plurality of micromirrors 17A for diffusing the laser light L transmitted through the half mirror 16 are formed on the diffuser plate 17. Each of the micromirrors 17A is, for example, substantially hemispherical and is arranged to be convex toward the concave surface 16A of the half mirror 16. For example, the plurality of micromirrors 17A are in contact with the surface on the side opposite to the concave surface 16A of the half mirror 16. Also, the plurality of micromirrors 17A are arranged two-dimensionally adjacent to each other.

[0032] For example, the half mirror 16 and the diffuser plate 17 are formed of a material such as resin or glass that transmits the laser light L. Also, for example, the half mirror 16 and the diffuser plate 17 are formed of a material having the same refractive index. The diffuser plate 17 reflects a part of the laser light L that has passed through the half mirror 16 on the surface of the micromirror 17A (i.e., the interface between the half mirror 16 and the diffuser plate 17). Since the condensing optical system 15 as a whole has translucency, a part of the external light incident from the outside is transmitted toward the eyeball EB.

[0033] Each of the micromirrors 17A diffuses the laser light L that has passed through the half mirror 16 in the specular reflection direction and in directions other than the specular reflection direction. Note that the specular reflection direction is the reflection direction when light is reflected in a direction equal to the incident angle. In this way, since each of the micromirrors 17A diffuses the laser light L in directions other than the specular reflection direction, a part of the laser light L diffused by the micromirrors 17A passes through the pupil of the eyeball EB and enters the retina without passing through the focal point P that is the center of the eyeball EB.

[0034] FIG. 3 shows an example of the configuration of the MEMS mirror 30. The MEMS mirror 30 includes a mirror portion 40, a first support portion 41, a first movable frame 42, a second support portion 43, a second movable frame 44, a connection portion 45, and a fixed frame 46.

[0035] The mirror portion 40 has a reflecting surface 40A that reflects incident light. The reflecting surface 40A is formed of a metal thin film such as gold (Au), aluminum (Al), silver (Ag), or an alloy of silver, for example. The shape of the reflecting surface 40A is, for example, circular.

[0036] The first support portions 41 are respectively arranged on the outside of the mirror portion 40 at positions facing each other with the second axis a2 interposed therebetween. The first support portions 41 are connected to the mirror portion 40 on the first axis a1 and support the mirror portion 40 so as to be swingable around the first axis a1.

[0037] The first movable frame 42 is a rectangular frame surrounding the mirror unit 40, and is connected to the mirror unit 40 via the first support portion 41 on the first axis a1. Piezoelectric elements 50 are respectively formed on the first movable frame 42 at positions facing each other with the first axis a1 interposed therebetween. In this way, by forming two piezoelectric elements 50 on the first movable frame 42, a pair of first actuators 51 is configured.

[0038] The pair of first actuators 51 are arranged at positions facing each other with the first axis a1 interposed therebetween. The first actuator 51 causes the mirror unit 40 to swing around the first axis a1 by applying a rotational torque around the first axis a1 to the mirror unit 40.

[0039] The second support portions 43 are respectively arranged outside the first movable frame 42 at positions facing each other with the first axis a1 interposed therebetween. The second support portions 43 are connected to the first movable frame 42 on the second axis a2, and support the first movable frame 42 and the mirror unit 40 so as to be swingable around the second axis a2. In the present embodiment, the second support portion 43 is a torsion bar extending along the second axis a2.

[0040] The second movable frame 44 is a rectangular frame surrounding the first movable frame 42, and is connected to the first movable frame 42 via the second support portion 43 on the second axis a2. Piezoelectric elements 50 are respectively formed on the second movable frame 44 at positions facing each other with the second axis a2 interposed therebetween. In this way, by forming two piezoelectric elements 50 on the second movable frame 44, a pair of second actuators 52 is configured.

[0041] The pair of second actuators 52 are arranged at positions facing each other with the second axis a2 interposed therebetween. The second actuator 52 causes the mirror unit 40 to swing around the second axis a2 by applying a rotational torque around the second axis a2 to the mirror unit 40 and the first movable frame 42.

[0042] The connection portions 45 are respectively arranged outside the second movable frame 44 at positions facing each other with the first axis a1 interposed therebetween. The connection portions 45 are connected to the second movable frame 44 on the second axis a2.

[0043] The fixed frame 46 is a rectangular frame surrounding the second movable frame 44, and is connected to the second movable frame 44 via a connecting portion 45 on the second axis a2.

[0044] In the present embodiment, the first axis a1 and the second axis a2 are orthogonal to each other. In the following description, the direction parallel to the first axis a1 is defined as the X direction, the direction parallel to the second axis a2 is defined as the Y direction, and the direction orthogonal to both the first axis a1 and the second axis a2 is defined as the Z direction.

[0045] FIG. 4 shows the positional relationship among the MEMS mirror 30, the condensing optical system 15, and the eyeball EB. As shown in FIG. 4, the MEMS mirror 30 is arranged such that the first axis a1, which is a single swing axis, passes through one of the foci of the concave surface 16A that is an elliptical surface. Specifically, the MEMS mirror 30 is arranged such that the intersection of the first axis a1 and the second axis a2 coincides with one of the foci of the concave surface 16A that is an elliptical surface. Due to this geometric relationship, the condensing point P of the laser beam L reflected by the concave surface 16A coincides with the other focus of the concave surface 16A.

[0046] The AR glass 10 is configured such that when the user wears it, the center of the eyeball EB coincides with the condensing point P. Therefore, when the user views the concave surface 16A of the half mirror 16 while wearing the AR glass 10, a part of the laser beam L reflected by the concave surface 16A passes through the pupil and enters the eyeball EB, is condensed at the condensing point P, and then enters the retina. The laser beam L that enters the eyeball EB mainly enters the region corresponding to the macula including the fovea centralis in the retina. The fovea centralis is a part where cells for recognizing color and shape are densely packed and has the highest resolution among the retina. The user recognizes an image by the laser beam L projected onto the retina.

[0047] The user can clearly recognize the portion located at the center in the line-of-sight direction among the images projected onto the concave surface 16A of the half mirror 16 by the MEMS mirror 30.

[0048] Note that, in Fig. 4, although the state where the concave surface 16A focuses the laser beam L on the focus point P within the YZ plane orthogonal to the first axis a1 is shown, the concave surface 16A is not limited to the YZ plane and can also focus the laser beam L on the focus point P within a plane other than the YZ plane including two foci.

[0049] In Fig. 4, the symbol Ld indicates a part of the laser beam L (hereinafter referred to as diffused light Ld) that has passed through the half mirror 16 and is diffused by the diffusion plate 17. As described above, the diffusion plate 17 diffuses the laser beam L incident through the half mirror 16 in the specular reflection direction and in directions other than the specular reflection direction by the micromirror 17A. Therefore, a part of the diffused light Ld enters the retina without passing through the focus point P which is the center of the eyeball EB. That is, the diffused light Ld also enters a region on the retina other than the region where the laser beam L reflected by the concave surface 16A is incident.

[0050] Figs. 5 to 7 will explain that the eye box expands and the viewing angle expands due to the AR glasses 10 according to the present embodiment.

[0051] Fig. 5 shows a state where the user is looking straight ahead. In this case, among the images projected onto the concave surface 16A of the half mirror 16, the laser beam L related mainly to the central image is reflected by the concave surface 16A, passes through the pupil, and enters the vicinity of the fovea of the retina. The symbol 60 represents an image recognized by the user in the brain. The symbol 61 represents a region (hereinafter referred to as a high-definition region) that the user can clearly recognize among the entire image 60. The high-definition region 61 corresponds to the region near the fovea of the retina. In the case of Fig. 5, the high-definition region 61 is located at the center of the image 60.

[0052] Fig. 6 shows a state where the user has moved the line of sight from the front to the right side. In this case, among the images projected onto the concave surface 16A of the half mirror 16, the laser beam L related mainly to the right-side image passes through the pupil and enters the vicinity of the fovea of the retina. In the case of Fig. 6, the high-definition region 61 is located on the right side of the image 60.

[0053] FIG. 7 shows a state where the user moves the line of sight from the front to the left side. In this case, among the images projected onto the concave surface 16A of the half mirror 16, the laser light L related to the mainly left-side image passes through the pupil and enters the vicinity of the fovea centralis of the retina. In the case of FIG. 7, the high-definition region 61 is located on the left side of the image 60.

[0054] As shown in FIGS. 5 to 7, in the AR glasses 10 according to the present embodiment, since the laser light L reflected by the concave surface 16A of the half mirror 16 is focused on the center of the eyeball EB, even if the position of the pupil moves as the user moves the line of sight, the laser light L in the region (corresponding to the above-described high-definition region 61) of the image projected onto the concave surface 16A that the user is gazing at always enters the vicinity of the fovea centralis of the retina. Thus, in the technology of the present disclosure, although the region of the image projected onto the concave surface 16A of the half mirror 16 that the user can clearly recognize is somewhat narrow, the region being gazed at can always be clearly recognized even when the line of sight is moved. That is, according to the technology of the present disclosure, the eyebox can be expanded with a simple configuration.

[0055] In addition, mainly diffused light Ld enters regions other than the region corresponding to the macula including the fovea centralis of the retina. This diffused light Ld includes that generated by diffusing the laser light L related to the peripheral region other than the region of the image projected onto the concave surface 16A that the user is gazing at by the diffuser 17. For this reason, in addition to the laser light L related to the central image of the image projected onto the concave surface 16A, the laser light L related to the peripheral image enters the retina as diffused light Ld. Therefore, although the resolution is low, the user can recognize the image also for the periphery of the region being gazed at, so that the viewing angle is widened.

[0056] Also, as described above, by making the refractive indices of the half mirror 16 and the diffuser 17 the same, refraction at the interface between the half mirror 16 and the diffuser 17 when external light passes through the condenser optical system 15 from the diffuser 17 side is suppressed. By suppressing the refraction of the external light in this way, the condenser optical system 15 can allow the user to observe the external scenery without distortion together with the image formed by the laser light L.

[0057] FIG. 8 illustrates a conventional retinal scanning method. In the conventional retinal scanning method, the laser beam L is focused near the center of the pupil and then enters the retina. FIG. 8 shows a state where the user is looking straight ahead. In this case, since the focusing point P of the laser beam L is located near the center of the pupil, the incident angle of the laser beam L entering the retina is wide. That is, in the conventional retinal scanning method, when the user is looking straight ahead, the viewing angle is wide and the entire image 60 can be recognized. On the other hand, in the conventional retinal scanning method, when the user moves the line of sight, the position of the pupil deviates from the focusing point P, so there is a problem that the eye box is narrow.

[0058] FIG. 9 shows a state where the user has moved the line of sight from the front to the right side in the conventional retinal scanning method. In this case, for example, the laser beam incident from the right side of the pupil is blocked by the iris located on the left side of the pupil. As a result, the image of the right region of the image 60 cannot be seen. Thus, even though the user tries to look to the right and moves the line of sight to the right, the user cannot see the image on the right, which causes stress.

[0059] On the other hand, in the retinal scanning method of the present disclosure, since the laser beam L is focused on the center of the eyeball EB, even if the position of the pupil moves when the user moves the line of sight, the user can always clearly recognize the vicinity of the center of the line of sight and does not feel stress as in the conventional case. The retinal scanning method of the present disclosure has a lower resolution in the peripheral region compared to the conventional retinal scanning method and cannot clearly recognize the periphery. However, humans can only clearly recognize only the vicinity of the center of the visual field in the first place, and when reading text or the like, it is necessary to move the eyes according to the area of interest. Therefore, as long as the user can always clearly recognize the vicinity of the center of the line of sight as in the retinal scanning method of the present disclosure, there is no practical problem even if the peripheral region cannot be clearly recognized.

[0060] [Modification Example] Next, various modifications of the above embodiment will be described. In the above embodiment, the diffuser plate 17 is configured to diffuse the laser light L incident through the half mirror 16 in the specular reflection direction and in directions other than the specular reflection direction. However, the diffuser plate 17 may be configured to diffuse the laser light L only in directions other than the specular reflection direction. For example, each of the micromirrors 17A may be shaped to diffuse the laser light L only in directions outside the angular range of ±5° centered on the specular reflection direction. By configuring the diffuser plate 17 in this way, the diffused light Ld enters only the peripheral region of the retina without passing through the focal point P which is the center of the eyeball EB. Therefore, it is possible to suppress a decrease in resolution of the high-definition region 61 due to the incidence of the diffused light Ld. As a result, the contrast of the image 60 is improved.

[0061] Further, in the above embodiment, the diffuser plate 17 is light transmissive, but the diffuser plate 17 may be light reflective. For example, a light reflecting film such as a metal film that highly reflects the laser light L is formed on the interface between the half mirror 16 and the diffuser plate 17 (that is, the surface of the micromirror 17A). Further, the diffuser plate 17 may be formed of a member having light reflectivity such as metal. When the diffuser plate 17 is thus made light reflective, external light does not pass through the condensing optical system 15, so that an optical scanning device for projecting an immersion-type video can be configured.

[0062] Also, the configuration of the MEMS mirror 30 shown in the above embodiment can be appropriately changed. For example, in the above embodiment, the first actuator 51 and the second actuator 52 are annular, but it is also possible to make one or both of the first actuator 51 and the second actuator 52 have a meander structure. Further, as the first support portion 41 and the second support portion 43, support members having a configuration other than a torsion bar can also be used.

[0063] In addition, the hardware configuration of the control device 20 can be variously modified. The processing unit of the control device 20 may be composed of one processor, or may be composed of a combination of two or more processors of the same type or different types (for example, a combination of a plurality of FPGAs (Field Programmable Gate Arrays), and / or a combination of a CPU and an FPGA).

[0064] All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Explanation of Signs

[0065] 10 AR glass 11 Frame 12 Lens 13 Temple 14 Module 15 Condensing optical system 16 Half mirror 16A Concave surface 17 Diffuser 17A Micromirror 20 Control device 20A FPGA 20B Memory 22 MEMS driver 24 Light emitting device 25 Laser driver 26 Wavelength multiplexing optical system 27 Laser light source 28 Collimator 30 MEMS mirror 40 Mirror part 40A Reflecting surface 41 First support part 42 First movable frame 43 Second support part 44 Second movable frame 45 Connection part 46 Fixed frame 50 Piezoelectric element 51 First actuator 52 Second actuator 60 Image 61 High-definition area EB Eyeball L Laser light Ld Diffused light P Focus point a1 First axis a2 Second axis

Claims

1. A light source that emits a laser beam, A mirror device having a movable mirror that swings around at least one axis, and deflecting the laser beam emitted from the light source by reflecting it with the movable mirror, A condensing optical system that condenses the laser beam deflected by the mirror device, comprising The condensing optical system includes a half mirror having a concave surface, and a diffusion plate formed with a plurality of micromirrors that diffuse the laser beam transmitted through the half mirror from the concave surface side, A light scanning device.

2. The condensing optical system condenses the laser beam deflected by the mirror device at the center of the eyeball, The light scanning device according to claim 1.

3. The concave surface is an elliptical surface, The swing axis of the movable mirror is located at one focus of the elliptical surface, and the center of the eyeball is located at the other focus, The light scanning device according to claim 2.

4. The diffusion plate diffuses the laser beam transmitted through the half mirror from the concave surface side in a direction other than the specular reflection direction, The light scanning device according to any one of claims 1 to 3.

5. The half mirror and the diffusion plate are formed of materials having the same refractive index, The light scanning device according to any one of claims 1 to 4.

6. The movable mirror is configured to be swingable around a first axis and a second axis that are orthogonal to each other, The light scanning device according to any one of claims 1 to 5.

Images