Optical device

Abstract

To enable accurate detection of vibration of a movable reflector.SOLUTION: An optical device is provided, comprising a movable reflector, a first light-emitting element attached to the movable reflector, and an aperture for allowing at least a portion of light emitted from the first light-emitting element to pass.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an optical device. [Background technology]

[0002] In recent years, various optical devices such as LiDAR (Light Detection And Ranging) have been developed. The optical devices may have a MEMS (Micro Electro Mechanical Systems) mirror that reflects light emitted from a light emitting element such as a laser diode (LD). For example, as described in Patent Document 1, the MEMS mirror may be provided with a piezoresistance element for detecting the oscillation of the MEMS mirror. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-56211 A Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors of the present application have considered attaching a light-emitting element to a movable reflector instead of or in addition to a piezoresistance element in order to detect the oscillation of a movable reflector such as a MEMS mirror. In this optical device, the oscillation of the movable reflector is detected by receiving light emitted from the light-emitting element with a light-receiving element such as a four-segment photodiode (PD). However, in this optical device, light different from the light emitted from the light-emitting element, such as external light, may be irradiated onto the light-receiving element. For this reason, there is room for improvement in the accuracy of detecting the oscillation of the movable reflector.

[0005] One example of a problem to be solved by the present invention is how to accurately detect the oscillation of a movable reflector. [Means for solving the problem]

[0006] The invention described in claim 1 is A movable reflector; A first light emitting element attached to the movable reflector; an aperture that passes at least a portion of the light emitted from the first light emitting element; An optical device comprising:

[0007] One aspect of the present invention is The optical device; A second light-emitting element; a second light receiving element that receives light emitted from the second light emitting element, reflected by the movable reflector, and reflected or scattered by an object present outside the optical device; The sensor device includes: [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view of an optical device according to an embodiment. [Diagram 2] 1 is an exploded perspective view of an optical device according to an embodiment. [Diagram 3] 2 is a cross-sectional view taken along line AA in FIG. 1. [Figure 4] FIG. 2 is a cross-sectional view of FIG. [Diagram 5] FIG. 2 is a cross-sectional view taken along CC in FIG. [Figure 6] 5A to 5C are diagrams for explaining an example of the operation of the optical device according to the embodiment. [Figure 7] 5A to 5C are diagrams for explaining an example of the operation of the optical device according to the embodiment. [Figure 8] FIG. 1 is a diagram showing a configuration of a sensor device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments and examples of the present invention will be described with reference to the drawings. In all the drawings, similar components are given similar reference numerals and the description will be omitted as appropriate.

[0010] Fig. 1 is a perspective view of an optical device 10 according to an embodiment. Fig. 2 is an exploded perspective view of the optical device 10 according to an embodiment. Fig. 3 is a cross-sectional view taken along line AA in Fig. 1. Fig. 4 is a cross-sectional view taken along line BB in Fig. 1. Fig. 5 is a cross-sectional view taken along line CC in Fig. 1.

[0011] 1 to 5, an arrow showing the first direction X, the second direction Y, or the third direction Z indicates that the direction from the base end of the arrow to the tip is the positive direction of the direction shown by the arrow, and the direction from the tip of the arrow to the base end is the negative direction of the direction shown by the arrow. In Fig. 5, a white circle with an X indicating the third direction Z indicates that the direction from the front of the paper to the back is the positive direction of the third direction Z, and the direction from the back of the paper to the front is the negative direction of the third direction Z. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other.

[0012] As shown in FIGS. 1 to 4, the optical device 10 includes a housing 100, an optical scanning device 200, a first light emitting element 300, a first light receiving element 400, a flexible substrate 500, a first magnetic circuit 610, a second magnetic circuit 620, and a heat sink 630. As shown in FIGS. 1 to 4, the housing 100 includes a base 102 and a lid 104. As shown in FIGS. 1 to 5, the optical scanning device 200 includes a movable reflector 210, a first frame 220, a pair of first torsion bars 230, a second frame 240, a pair of second torsion bars 250, a first terminal 262, and a second terminal 264. The pair of first torsion bars 230 includes a first metal bar 232 and a second metal bar 234. The pair of second torsion bars 250 includes a third metal bar 252 and a fourth metal bar 254.

[0013] 1 to 5, the positive direction of the first direction X is the direction from the side where the second metal bar 234 is located to the side where the first metal bar 232 is located. The negative direction of the first direction X is the direction from the side where the first metal bar 232 is located to the side where the second metal bar 234 is located. The positive direction of the second direction Y is the direction from the side where the fourth metal bar 254 is located to the side where the third metal bar 252 is located. The negative direction of the second direction Y is the direction from the side where the third metal bar 252 is located to the side where the fourth metal bar 254 is located. The positive direction of the third direction Z is the direction from the side where the base 102 is located to the side where the lid 104 is located. The negative direction of the third direction Z is the direction from the side where the lid 104 is located to the side where the base 102 is located.

[0014] The housing 100 houses the optical scanning device 200, the first light-emitting element 300, the first light-receiving element 400, at least a portion of the flexible substrate 500, a first magnetic circuit 610, a second magnetic circuit 620, and a heat sink 630. The lid 104 is attached to a surface of the base 102 on the positive side in the third direction Z.

[0015] 1, 3 and 4, the optical scanning device 200 is mounted on the surface side of the base 102 in the positive direction of the third direction Z, with at least a portion of the movable reflector 210, at least a portion of the first frame 220, and at least a portion of the pair of first torsion bars 230 exposed from the opening 150 of the lid 104. Also, as viewed from the positive direction of the third direction Z, at least a portion of the second frame 240 and at least a portion of the pair of second torsion bars 250 are covered by the lid 104. Therefore, as viewed from the third direction Z, it is possible to make it difficult for external light to be irradiated to the first light receiving element 400, compared to the case where at least a portion of the second frame 240 and at least a portion of the pair of second torsion bars 250 are exposed from the lid 104. Furthermore, compared to the case where at least a portion of the pair of second torsion bars 250 is exposed from the lid 104, even if the diffusely reflected light inside the container 100 of the distance measuring light from outside the optical scanning device 200 is irradiated onto a metal portion of the second torsion bar 250 with a relatively high reflectivity, it is possible to prevent the reflected light from the second torsion bar 250 from returning as stray light to the distance measuring light receiving element provided outside the optical scanning device 200.

[0016] As shown in FIG. 3 and FIG. 4, the movable reflector 210 has a movable support base 212 and a reflector 214. As shown in FIG. 5, the movable support base 212 includes a first metal body 212a, a second metal body 212b, and a resin base 212c. At least a portion of the first metal body 212a is located on the positive side of the first direction X with respect to at least a portion of the second metal body 212b. At least a portion of the second metal body 212b is located on the negative side of the first direction X with respect to at least a portion of the first metal body 212a. The resin base 212c covers at least a portion of the surface of the first metal body 212a on the positive side of the third direction Z and at least a portion of the surface of the second metal body 212b on the positive side of the third direction Z. The reflector 214 is located on the surface of the resin base 212c on the positive side of the third direction Z. The surface of the reflector 214 on the positive side in the third direction Z serves as a reflective surface that reflects light, such as distance measuring light, from outside the optical scanning device 200. The reflector 214 is integral with the movable support base 212 and is capable of swinging.

[0017] 5, the first frame body 220 includes a first metal frame body 222 and a first resin body 224. When viewed from the third direction Z, the first metal frame body 222 is located in at least a part of a region surrounding the movable reflector 210 and the pair of first torsion bars 230. At least a part of the first metal frame body 222 is sealed by the first resin body 224. When the first resin body 224 is provided, unnecessary vibration of the first frame body 220 can be suppressed compared to when the first resin body 224 is not provided.

[0018] The first metal bar 232 connects the movable reflector 210 and the first frame 220. The first metal bar 232 extends parallel to the first direction X. Specifically, as shown in FIG. 5, an end of the first metal bar 232 on the negative side in the first direction X is connected to the first metal body 212a. An end of the first metal bar 232 on the positive side in the first direction X is connected to an inner edge of an end of the first metal frame 222 on the positive side in the first direction X.

[0019] The second metal bar 234 connects the movable reflector 210 and the first frame 220. The second metal bar 234 extends parallel to the first direction X. Specifically, as shown in FIG. 5, an end of the second metal bar 234 on the positive side in the first direction X is connected to the second metal body 212b. An end of the second metal bar 234 on the negative side in the first direction X is connected to an inner edge of an end of the first metal frame 222 on the negative side in the first direction X.

[0020] 2, 3, and 4, a first permanent magnet 216 is provided on the surface side of the movable reflector 210 in the negative direction in the third direction Z. In the example shown in FIGS. 2, 3, and 4, the first permanent magnet 216 is located on the negative side of the first direction X with respect to the center of the movable reflector 210 in the first direction X. When the first permanent magnet 216 receives the magnetic flux generated from the first magnetic circuit 610, the movable reflector 210 swings relative to the first frame 220 with the pair of first torsion bars 230 as the rotation axis.

[0021] Specifically, as shown in FIG. 2, FIG. 3, and FIG. 4, the first magnetic circuit 610 includes a first coil 612, a first yoke 614, and a pair of second yokes 616. The first coil 612 is wound around the first yoke 614. As shown in FIG. 3 and FIG. 4, the first yoke 614 extends parallel to the second direction Y in a space on the negative side of the third direction Z with respect to the first light emitting element 300 and the flexible substrate 500. Each of the pair of second yokes 616 is connected to the end of the first yoke 614 on the positive side of the second direction Y and the end of the first yoke 614 on the negative side of the second direction Y. As shown in FIG. 4, the tips of the pair of second yokes 616 face each other via a space located on the negative side of the third direction Z with respect to the movable reflector 210. When an AC current flows through the first coil 612, an AC magnetic field is generated from each tip of the pair of second yokes 616. When the first permanent magnet 216 receives this AC magnetic field, the movable reflector 210 swings relative to the first frame 220 with the pair of first torsion bars 230 as the rotation axis.

[0022] 5, the second frame body 240 includes a second metal frame body 242 and a second resin body 244. When viewed from the third direction Z, the second metal frame body 242 is located in at least a part of a region surrounding the first frame body 220 and the pair of second torsion bars 250. At least a part of the second metal frame body 242 is sealed by the second resin body 244. When the second resin body 244 is provided, unnecessary vibration of the second frame body 240 can be suppressed compared to when the second resin body 244 is not provided.

[0023] The third metal bar 252 connects the first frame 220 and the second frame 240. The third metal bar 252 extends parallel to the second direction Y. Specifically, as shown in FIG. 5, an end of the third metal bar 252 on the negative side in the second direction Y is connected to an outer edge of the first metal frame 222 on the positive side in the second direction Y and in the center in the first direction X. An end of the third metal bar 252 on the positive side in the second direction Y is connected to an inner edge of the second metal frame 242 on the positive side in the second direction Y and in the center in the first direction X.

[0024] The fourth metal bar 254 connects the first frame body 220 and the second frame body 240. The fourth metal bar 254 extends parallel to the second direction Y. Specifically, as shown in FIG. 5, an end of the fourth metal bar 254 on the positive side in the second direction Y is connected to the outer edge of the first metal frame body 222 on the negative side in the second direction Y and in the center in the first direction X. An end of the fourth metal bar 254 on the negative side in the second direction Y is connected to the inner edge of the second metal frame body 242 on the negative side in the second direction Y and in the center in the first direction X.

[0025] As shown in Fig. 2 and Fig. 3, a pair of second permanent magnets 226 are provided on both ends of the first frame body 220 in the first direction X. In the example shown in Fig. 2 and Fig. 3, each second permanent magnet 226 is provided on the surface side of the first frame body 220 in the negative direction of the third direction Z. When each of the pair of second permanent magnets 226 receives the magnetic flux generated from the second magnetic circuit 620, the first frame body 220 swings relative to the second frame body 240 around the pair of second torsion bars 250 as the rotation axis. As a result, the movable reflector 210 swings relative to the second frame body 240, integrally with the first frame body 220 and the pair of first torsion bars 230, around the second torsion bars 250 as the rotation axis.

[0026] Specifically, as shown in FIG. 2, the second magnetic circuit 620 includes a pair of second coils 622 located on the positive side of the first direction X, and another pair of second coils 622 located on the negative side of the first direction X. The pair of second coils 622 located on the positive side of the first direction X face each other via the end of the first frame 220 on the positive side of the first direction X. When an AC current flows through the pair of second coils 622, an AC magnetic field is generated from the pair of second coils 622. In addition, the other pair of second coils 622 located on the negative side of the first direction X face each other via the end of the movable reflector 210 on the negative side of the first direction X. When an AC current flows through the other pair of second coils 622, an AC magnetic field is generated from the other pair of second coils 622. When the second permanent magnets 226 provided on both ends of the first frame body 220 in the first direction X receive this AC magnetic field, the first frame body 220 swings relative to the second frame body 240, with the pair of second frame bodies 240 serving as a rotation axis. As a result, the movable reflector 210, integrated with the first frame body 220 and the pair of first torsion bars 230, swings relative to the second frame body 240, with the second torsion bar 250 serving as a rotation axis.

[0027] In the embodiment, as viewed from the positive direction of the third direction Z, at least a portion of each of the four second coils 622 is covered by the lid 104. Therefore, compared to a case where at least a portion of each second coil 622 is exposed from the lid 104, even if diffuse reflection light of the distance measurement light from the outside of the optical scanning device 200 inside the housing 100 is irradiated onto a metal part of the second coil 622 with a relatively high reflectance, it is possible to suppress the reflected light from the second coil 622 from returning as stray light to a light receiving element for distance measurement provided outside the optical scanning device 200. Also, as viewed from the positive direction of the third direction Z, the lid 104 covers metal parts with a relatively high reflectance, such as the wiring connecting the flexible substrate 500 and the first coil 612 and the soldered part of the wiring and the flexible substrate 500, the wiring connecting the flexible substrate 500 and the second coil 622 and the soldered part of the wiring and the flexible substrate 500. Therefore, compared to a case where the metal portion is not covered by the lid 104, even if the diffusely reflected light is irradiated onto the metal portion, the reflected light from the metal portion can be prevented from returning as stray light to a distance measuring light receiving element provided outside the optical scanning device 200.

[0028] The heat generated from the second magnetic circuit 620 is transferred to the heat sink 630 via a heat transfer agent (not shown). This allows the heat generated from the second magnetic circuit 620 to escape to the outside of the optical device 10.

[0029] The first terminal 262 and the second terminal 264 are connected to the second metal frame 242. Specifically, as shown in FIG. 5, the first terminal 262 is connected to the outer edge of the second metal frame 242 on the positive side of the second direction Y and the central part in the first direction X. The second terminal 264 is connected to the outer edge of the second metal frame 242 on the positive side of the second direction Y and the part shifted from the central part in the first direction X to the negative side of the first direction X. However, the positions at which the first terminal 262 and the second terminal 264 are provided are not limited to this example. In the embodiment, the first terminal 262 and the second terminal 264 are pressed against the flexible substrate 500 by the lid 104. Therefore, compared to a case where the first terminal 262 and the second terminal 264 are not pressed against the flexible substrate 500 by the lid 104, it is easier to ensure the conduction between the first terminal 262 and the flexible substrate 500 and the conduction between the second terminal 264 and the flexible substrate 500.

[0030] The first light emitting element 300 is, for example, a light emitting diode (LED). The first light emitting element 300 is attached to the negative side of the movable support base 212 in the third direction Z. Therefore, the first light emitting element 300 is capable of swinging integrally with the movable reflector 210.

[0031] One of the anode and the cathode of the first light emitting element 300 is electrically connected to the first metal body 212a. The other of the anode and the cathode of the first light emitting element 300 is electrically connected to the second metal body 212b. In the embodiment, a drive current for the first light emitting element 300 can be passed between the first terminal 262 and the second terminal 264.

[0032] Specifically, as shown in FIG. 5, the first metal frame 222 is provided with two first dividing sections 222a. One of the two first dividing sections 222a is provided between the connection portion between the first metal frame 222 and the first metal bar 232 and the connection portion between the first metal frame 222 and the fourth metal bar 254. The other of the two first dividing sections 222a is provided between the connection portion between the first metal frame 222 and the second metal bar 234 and the connection portion between the first metal frame 222 and the third metal bar 252. This prevents a short circuit between the first metal body 212a and the second metal body 212b via the first metal frame 222. Also, a short circuit between the third metal bar 252 and the fourth metal bar 254 via the first metal frame 222 is prevented.

[0033] 5, the second metal frame 242 is provided with a second dividing portion 242a on the positive side of the second direction Y of the second metal frame 242 and another second dividing portion 242a on the negative side of the second direction Y of the second metal frame 242. The second dividing portion 242a on the positive side of the second direction Y of the second metal frame 242 is provided in a portion shifted from the positive side of the second direction Y of the second metal frame 242 and the center in the first direction X to the negative side of the first direction X. In the example shown in FIG. 5, the second dividing portion 242a on the positive side of the second direction Y of the second metal frame 242 is located between the connection portion between the second metal frame 242 and the first terminal 262 and the connection portion between the second metal frame 242 and the second terminal 264. The other second dividing portion 242a on the negative side in the second direction Y of the second metal frame 242 is provided in a portion on the negative side in the second direction Y of the second metal frame 242 and shifted from the center in the first direction X to the positive side in the first direction X. These two second dividing portions 242a prevent a short circuit between the first terminal 262 and the second terminal 264 via the second metal frame 242.

[0034] In the embodiment, from the first terminal 262 to the second terminal 264, the third metal bar 252, a portion of the first metal frame 222 between the connection portion of the first metal frame 222 and the third metal bar 252 and the connection portion of the first metal frame 222 and the first metal bar 232, the first metal bar 232, the first metal body 212a, the first light-emitting element 300, the second metal body 212b, the second metal bar 234, and the first metal frame 232. A driving current for the first light-emitting element 300 can be passed through a portion in the second metal frame 242 between the connection portion of the first metal frame 222 and the second metal bar 234 and the connection portion of the first metal frame 222 and the fourth metal bar 254, the fourth metal bar 254, and a portion in the second metal frame 242 between the connection portion of the second metal frame 242 and the fourth metal bar 254 and the connection portion of the second metal frame 242 and the second terminal 264. In this example, the driving current flows from the first terminal 262 to the second terminal 264. However, the driving current may also flow from the second terminal 264 to the first terminal 262.

[0035] 3 and 4, the first light receiving element 400 is located on the negative side of the first light emitting element 300 in the third direction Z. At least a portion of the light shield 110 of the base 102 is located between the first light emitting element 300 and the first light receiving element 400 in the third direction Z. The light shield 110 defines an aperture 112. The aperture 112 passes at least a portion of the light emitted from the first light emitting element 300. The first light receiving element 400 receives the light that has passed through the aperture 112.

[0036] In the example shown in FIG. 3 and FIG. 4, the aperture 112 includes a narrow hole 114 and a wide hole 116. The narrow hole 114 penetrates the surface of the light blocking body 110 on the positive side in the third direction Z. The inner surface of the narrow hole 114 is substantially parallel to the third direction Z. As a result, the opening area of ​​the narrow hole 114 perpendicular to the third direction Z is constant regardless of the position in the third direction Z. The wide hole 116 penetrates the surface of the light blocking body 110 on the negative side in the third direction Z. The end of the wide hole 116 on the positive side in the third direction Z is connected to the end of the narrow hole 114 on the negative side in the third direction Z. The opening area of ​​the wide hole 116 perpendicular to the third direction Z is larger than the opening area of ​​the narrow hole 114 perpendicular to the third direction Z. 3 and 4, the inner surface of the wide hole 116 is inclined with respect to the third direction Z. As a result, the opening area of ​​the wide hole 116 perpendicular to the third direction Z increases from the positive direction to the negative direction of the third direction Z. However, the shape of the aperture 112 is not limited to the example shown in FIGS. 3 and 4. For example, the inner surface of the wide hole 116 may be substantially parallel to the third direction Z. In this case, the opening area of ​​the wide hole 116 perpendicular to the third direction Z is constant regardless of the position in the third direction Z.

[0037] The first light receiving element 400 is, for example, a four-part PD (photodiode). As shown in FIG. 2, FIG. 3 and FIG. 4, the surface of the first light receiving element 400 on the positive side in the third direction Z has a light receiving area 410. The light receiving area 410 includes a first light receiving area 412, a second light receiving area 414, a third light receiving area 416 and a fourth light receiving area 418. The first light receiving area 412, the second light receiving area 414, the third light receiving area 416 and the fourth light receiving area 418 are divided from each other. Specifically, the first light receiving area 412 is located on the positive side of the first direction X and the positive side of the second direction Y with respect to the center of the first direction X and the second direction Y of the light receiving area 410. The second light receiving area 414 is located on the negative side of the first direction X and the positive side of the second direction Y with respect to the center of the first direction X and the second direction Y of the light receiving area 410. The third light receiving area 416 is located on the negative side in the first direction X and the negative side in the second direction Y with respect to the center of the light receiving area 410 in the first direction X and the second direction Y. The fourth light receiving area 418 is located on the positive side in the first direction X and the negative side in the second direction Y with respect to the center of the light receiving area 410 in the first direction X and the second direction Y.

[0038] The flexible substrate 500 is, for example, a flexible printed circuit (FPC). The flexible substrate 500 is electrically connected to the first light receiving element 400. The flexible substrate 500 is provided to transmit a signal generated in the first light receiving element 400 by receiving light by the first light receiving element 400. The flexible substrate 500 is drawn out from the housing 100 toward the negative side of the second direction Y.

[0039] 6 and 7 are diagrams for explaining an example of the operation of the optical device 10 according to the embodiment. In Fig. 6 and Fig. 7, a white circle with a black dot indicating the first direction X indicates that the direction from the back of the paper to the front is the positive direction of the first direction X, and the direction from the front of the paper to the back is the negative direction of the first direction X. In Fig. 6 and Fig. 7, for the sake of explanation, only the movable support base 212 of the movable reflector 210 and the reflector 214 are illustrated.

[0040] 6 and 7, the first reference line R1, the second reference line R2, and the center line C are virtually illustrated for the purpose of explanation. When viewed from the positive direction of the first direction X, the first reference line R1 passes through the center of the oscillation of the pair of first torsion bars 230 of the movable reflector 210 in parallel to the third direction Z. When viewed from the positive direction of the first direction X, the second reference line R2 passes through the center of the oscillation of the pair of first torsion bars 230 of the movable reflector 210 in parallel to the second direction Y. When viewed from the positive direction of the first direction X, the center line C passes through the center of the movable reflector 210 in a direction perpendicular to the surface of the reflector 214 on the positive side of the third direction Z.

[0041] 6 and 7, the first reference line R1 passes through the center of the aperture 112 in the first direction X and the second direction Y and the center of the light receiving area 410 in the first direction X and the second direction Y. In addition, in the example shown in Fig. 6 and 7, when viewed from the positive direction of the first direction X, the light emitting point from which the light L is emitted from the first light emitting element 300 is shifted along the center line C to the side where the first light emitting element 300 is located, with respect to the center of the oscillation around the pair of first torsion bars 230 of the movable reflector 210.

[0042] The state shown in Fig. 6 will be described. In the state shown in Fig. 6, the oscillation angle around the pair of first torsion bars 230 of the movable reflector 210 is 0° when viewed from the positive direction of the first direction X. Therefore, when viewed from the positive direction of the first direction X, the center line C overlaps with the first reference line R1 and the first direction X.

[0043] The light L spreads out toward the periphery of the center line C as it moves away from the light emitting point of the first light emitting element 300. The portion of the light L irradiated toward the narrow hole 114 passes through the narrow hole 114 in a direction parallel to the center line C as transmitted light PL. In contrast, the portion of the light L irradiated toward the periphery of the narrow hole 114 is blocked by the peripheral portion of the narrow hole 114 on the surface of the light blocking body 110 on the positive side in the third direction Z.

[0044] The passing light PL passes through the narrow hole 114 and then through the wide hole 116. The passing light PL widens as it moves away from the light emitting point of the first light emitting element 300. Meanwhile, the opening area of ​​the wide hole 116 perpendicular to the third direction Z is larger than the opening area of ​​the narrow hole 114 perpendicular to the third direction Z. Therefore, the passing light PL can pass through the wide hole 116 without being blocked by the inner side surface of the wide hole 116. After passing through the wide hole 116, the passing light PL is irradiated to the center and its periphery in the first direction X and second direction Y of the light receiving area 410.

[0045] The state shown in Fig. 7 will be described. In the state shown in Fig. 7, the movable reflector 210 is rotated counterclockwise around the pair of first torsion bars 230, as compared to a state in which the oscillation angle around the pair of first torsion bars 230 is 0°, as viewed from the positive side of the first direction X. As a result, the center line C is rotated counterclockwise with respect to the first reference line R1, as viewed from the positive side of the first direction X.

[0046] The light L spreads toward the periphery of the center line C as it moves away from the light emitting point of the first light emitting element 300. The portion of the light L irradiated toward the narrow hole 114 passes through the narrow hole 114 in a direction inclined with respect to the first reference line R1 as transmitted light PL. Specifically, the transmitted light PL is inclined on the opposite side to the side to which the center line C is inclined with respect to the first reference line R1. In contrast, the portion of the light L irradiated toward the periphery of the narrow hole 114 is blocked by the peripheral portion of the narrow hole 114 on the surface of the light blocking body 110 on the positive side in the third direction Z.

[0047] The passing light PL passes through the narrow hole 114 and then through the wide hole 116. The passing light PL widens as it moves away from the light emitting point of the first light emitting element 300. Meanwhile, the opening area of ​​the wide hole 116 perpendicular to the third direction Z is larger than the opening area of ​​the narrow hole 114 perpendicular to the third direction Z. Therefore, the passing light PL can pass through the wide hole 116 without being blocked by the inner surface of the wide hole 116. After passing through the wide hole 116, the passing light PL is irradiated to a position shifted toward the negative side of the second direction Y with respect to the center of the light receiving area 410 in the first direction X and the second direction Y and its periphery.

[0048] 6 and 7, when a part of the light L passes through the aperture 112, the spot generated in the light receiving area 410 by the passing light PL moves to the opposite side of the side where the center line C is inclined with respect to the first reference line R1. For example, as shown in Fig. 6 and 7, when the movable reflector 210 swings around the pair of first torsion bars 230, the spot generated in the light receiving area 410 by the passing light PL moves to the opposite side of the side where the center line C is inclined with respect to the first reference line R1 in the second direction Y. Also, when the movable reflector 210 swings around the pair of second torsion bars 250, the spot generated in the light receiving area 410 by the passing light PL moves to the opposite side of the side where the center line C is inclined with respect to the first reference line R1 in the first direction X.

[0049] In the embodiment, the oscillation of the movable reflector 210 can be detected according to the ratio of the intensity of the signals generated by the light L in each of the first light receiving area 412, the second light receiving area 414, the third light receiving area 416, and the fourth light receiving area 418. Specifically, the oscillation angle around the pair of second torsion bars 250 of the movable reflector 210 is estimated by a first tilt error rate RX shown by the following formula (1). Also, the oscillation angle around the pair of first torsion bars 230 of the movable reflector 210 is estimated by a second tilt error rate RY shown by the following formula (2). RX=EX / (A+B+C+D) (1) RY=EY / (A+B+C+D) (2) EX = (A + D) - (B + C) (3) EY = (A + B) - (C + D) (4) Here, the first tilt error amount EX is the tilt error amount of the swing around the pair of second torsion bars 250 of the movable reflector 210. The second tilt error amount EY is the tilt error amount of the swing around the pair of first torsion bars 230 of the movable reflector 210. A, B, C, and D are the intensities of signals generated in the first light receiving area 412, the second light receiving area 414, the third light receiving area 416, and the fourth light receiving area 418 by the passing light PL, respectively. The intensities A, B, C, and D become higher as the spots of light irradiated on the first light receiving area 412, the second light receiving area 414, the third light receiving area 416, and the fourth light receiving area 418 become larger.

[0050] The set of the first light receiving area 412 and the fourth light receiving area 418 and the set of the second light receiving area 414 and the third light receiving area 416 are divided in the movement direction of a spot generated in the light receiving area 410 by the passing light PL when the movable reflector 210 swings around the pair of second torsion bars 250. The movement of the spot in the first direction X changes the relationship between the irradiation area of ​​the spot in the first light receiving area 412 and the fourth light receiving area 418 and the irradiation area of ​​the spot in the second light receiving area 414 and the third light receiving area 416. Therefore, the first tilt error rate RX changes depending on the position of the spot in the first direction X in the light receiving area 410. Therefore, the swing angle of the movable reflector 210 around the pair of second torsion bars 250 can be estimated from the first tilt error rate RX.

[0051] The set of the first light receiving area 412 and the second light receiving area 414 and the set of the third light receiving area 416 and the fourth light receiving area 418 are divided in the movement direction of a spot generated in the light receiving area 410 by the passing light PL when the movable reflector 210 swings around the pair of first torsion bars 230. The movement of the spot in the second direction Y changes the relationship between the irradiation area of ​​the spot in the first light receiving area 412 and the second light receiving area 414 and the irradiation area of ​​the spot in the third light receiving area 416 and the fourth light receiving area 418. Therefore, the second tilt error rate RY changes depending on the position of the spot in the second direction Y in the light receiving area 410. Therefore, the swing angle of the movable reflector 210 around the pair of first torsion bars 230 can be estimated from the second tilt error rate RY.

[0052] In the embodiment, at least a portion of the light L passes through the aperture 112. Therefore, compared to a case where the light shielding body 110 is not provided, it is possible to suppress light different from the light L, such as external light, from being irradiated onto the light receiving area 410. Therefore, compared to a case where the light shielding body 110 is not provided, it is possible to detect the oscillation of the movable reflector 210 more accurately.

[0053] Furthermore, in the embodiment, the portion of light L irradiated toward the periphery of narrow hole 114 is blocked by the peripheral portion of narrow hole 114 on the surface of light shield 110 on the positive side in third direction Z. This makes it possible to make the spot generated in light receiving area 410 by passing light PL smaller than when light shield 110 is not provided. This makes it possible to make the fluctuation amount of first tilt error rate RX and the fluctuation amount of second tilt error rate RY larger than when light shield 110 is not provided, thereby increasing the sensitivity of detection of oscillation of movable reflector 210.

[0054] In one example, the spot generated in the light receiving area 410 by the passing light PL may be smaller than the light receiving area 410 when viewed from the positive direction of the third direction Z. Specifically, the length in the first direction X of the spot generated in the light receiving area 410 by the passing light PL may be, for example, longer than 0.3 times and less than 0.7 times the length in the first direction X of the light receiving area 410. When the length of the spot is within the above numerical range, the amount of fluctuation of the first tilt error amount EX can be increased compared to when the length of the spot is equal to or less than the lower limit of the above numerical range, and the SN ratio of the detection of the oscillation around the pair of second torsion bars 250 of the movable reflector 210 can be increased. When the length of the spot is within the above numerical range, the amount of fluctuation of the first tilt error rate RX can be increased compared to when the length of the spot is greater than the upper limit of the above numerical range, and the sensitivity of the detection of the oscillation around the pair of second torsion bars 250 of the movable reflector 210 can be increased. The length in the second direction Y of the spot generated in the light receiving area 410 by the passing light PL may also be, for example, more than 0.3 times and less than 0.7 times the length in the second direction Y of the light receiving area 410.

[0055] Furthermore, the amplitude in the first direction X of the spot generated in the light receiving area 410 by the passing light PL may be, for example, greater than 0.05 times and less than 0.1 times the length in the first direction X of the light receiving area 410. When the amplitude of the spot is within the above-mentioned numerical range, the fluctuation amount of the first tilt error rate RX can be increased compared to when the amplitude of the spot is equal to or less than the lower limit of the above-mentioned numerical range, and the sensitivity of detection of the oscillation around the pair of second torsion bars 250 of the movable reflector 210 can be increased. When the amplitude of the spot is within the above-mentioned numerical range, it is possible to suppress at least a part of the spot from being irradiated outside the first direction X of the light receiving area 410 compared to when the amplitude of the spot is equal to or more than the upper limit of the above-mentioned numerical range. The amplitude in the second direction Y of the spot generated in the light receiving area 410 by the passing light PL may also be, for example, greater than 0.05 times and less than 0.1 times the length in the second direction Y of the light receiving area 410.

[0056] The size and amplitude of the spot generated in the light receiving area 410 by the passing light PL can be changed by appropriately adjusting conditions such as the opening area perpendicular to the third direction Z of the narrow hole 114, the distance between the light emitting point of the first light emitting element 300 and the end of the narrow hole 114 on the positive side in the third direction Z, the distance between the light emitting point of the first light emitting element 300 and the light receiving area 410 of the first light receiving element 400, and the distance between the light emitting point of the first light emitting element 300 and the center of oscillation of the movable reflector 210.

[0057] Aperture 112 may transmit the entire light L. Even in this case, when the opening area of ​​aperture 112 perpendicular to third direction Z is appropriately set, irradiation of light other than light L onto light receiving area 410 can be suppressed, compared to the case where light blocking body 110 is not provided.

[0058] In the embodiment, the opening area of ​​at least a portion of the aperture 112 on the side where the first light receiving element 400 is located is larger than the opening area of ​​at least a portion of the aperture 112 on the side where the first light emitting element 300 is located. Specifically, the opening area of ​​the wide hole 116 perpendicular to the third direction Z is larger than the opening area of ​​the narrow hole 114 perpendicular to the third direction Z. Therefore, the irradiation area of ​​the light receiving area 410 with the passing light PL can be made larger compared to the case where the opening area of ​​the wide hole 116 perpendicular to the third direction Z is equal to or smaller than the opening area of ​​the narrow hole 114 perpendicular to the third direction Z. Also, the strength of the light shield 110 can be made higher compared to the case where the peripheral portion of the wide hole 116 of the light shield 110 does not exist.

[0059] 6 and 7, the inner side surface of the wide hole 116 is inclined with respect to the third direction Z. However, the inner side surface of the wide hole 116 may be substantially parallel to the third direction Z. Even in this example, the irradiation area of ​​the light receiving area 410 with the passing light PL can be made larger than when the opening area of ​​the wide hole 116 perpendicular to the third direction Z is equal to or smaller than the opening area of ​​the narrow hole 114 perpendicular to the third direction Z. Furthermore, the strength of the light shielding body 110 can be made higher than when the peripheral portion of the wide hole 116 of the light shielding body 110 does not exist. EXAMPLES

[0060] FIG. 8 is a diagram showing a configuration of a sensor device 20 according to an embodiment.

[0061] The sensor device 20 includes the optical device 10 according to the embodiment. The sensor device 20 further includes a second light emitting element 12, a second light receiving element 14, and a beam splitter 16. In the embodiment, the sensor device 20 is a LiDAR (Light Detection And Ranging).

[0062] The second light-emitting element 12 is, for example, a laser diode (LD). As indicated by a solid arrow extending from the second light-emitting element 12 via the beam splitter 16 and the movable reflector 210, the light emitted from the second light-emitting element 12 passes through the beam splitter 16 and is reflected by the movable reflector 210. The light reflected by the movable reflector 210 is reflected or scattered by an object (not shown) existing outside the optical device 10.

[0063] The second light receiving element 14 is, for example, an avalanche photodiode (APD). As indicated by the solid arrow extending to the second light receiving element 14 via the optical device 10 and the beam splitter 16, the second light receiving element 14 receives light emitted from the second light emitting element 12, reflected by the movable reflector 210, and reflected or scattered by an object (not shown) present outside the optical device 10. In the embodiment, the light received by the second light receiving element 14 is reflected or scattered by the object, reflected by the movable reflector 210 and the beam splitter 16, and reaches the second light receiving element 14.

[0064] The structure of the sensor device 20 is not limited to the structure according to the embodiment. For example, in the embodiment, the optical axis of the light reflected by the movable reflector 210 and irradiated to an object existing outside the optical device 10 coincides with the optical axis of the light reflected or scattered by the object. However, the optical axis of the light reflected by the movable reflector 210 and irradiated to an object existing outside the optical device 10 may be shifted from the optical axis of the light reflected or scattered by the object. In this case, the light reflected or scattered by the object reaches the second light receiving element 14 without being reflected by the movable reflector 210.

[0065] Although the embodiment and examples of the present invention have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0066] 6, in the embodiment, when the oscillation angle around the pair of first torsion bars 230 of the movable reflector 210 is 0°, the light L is irradiated to the center of the light receiving area 410 in the first direction X and the second direction Y and its periphery. However, when the oscillation angle around the pair of first torsion bars 230 of the movable reflector 210 is 0°, the light L may be irradiated to a position shifted from the center of the light receiving area 410 in the first direction X and the second direction Y and its periphery. Even in this case, the oscillation angle around the pair of first torsion bars 230 of the movable reflector 210 can be estimated by referring to the first tilt error rate RX and the second tilt error rate RY.

[0067] In the embodiment, the first light receiving element 400 is a four-split PD. However, when the movable reflector 210 rotates only about a single rotation axis, the first light receiving element 400 may be a two-split PD. In this example, the light receiving area 410 has two light receiving areas that are split in the moving direction of a spot generated in the light receiving area 410 by the light emitted from the first light emitting element 300. When the movable reflector 210 rotates only about a single rotation axis, the tilt error rate can be measured more easily when only two split light receiving areas are provided than when four split light receiving areas are provided. [Explanation of symbols]

[0068] 10 Optical equipment 12 Second light-emitting element 14 Second light receiving element 16 Beam splitter 20 Sensor device 100 units 102 Base 104 Lid 110 Shading body 112 Aperture 114 Narrow Hole 116 Wide hole 150 aperture 200 Optical Scanning Device 210 Movable reflector 212 Movable support platform 212a First metal body 212b Second metal body 212c resin stand 214 Reflector 216 First permanent magnet 220 First Frame 222 First metal frame 222a First Separation 224 First resin body 226 Second permanent magnet 230 First Torsion Bar 232 No. 1 Metal Bar 234 Second Metal Bar 240 Second Frame 242 Second metal frame 242a Second division 244 Second Resin Body 250 2nd torsion bar 252 3rd Metal Bar 254 4th Metal Bar 262 1st terminal 264 2nd terminal 300 First light emitting element 400 First light receiving element 410 Light receiving area 412 First light receiving area 414 Second light receiving area 416 Third receiving area 418 4th receiving area 500 Flexible PCB 610 First magnetic circuit 612 First coil 614 First York 616 2nd York 620 Second magnetic circuit 622 Second coil 630 Heatsink C center line L light PL passing light R1 First Reference Line R2 2nd reference line X 1st direction Y Second direction Z 3rd direction

Claims

[Claim 1] A movable reflector; A first light emitting element attached to the movable reflector; an aperture that passes at least a portion of the light emitted from the first light emitting element; An optical device comprising:

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