Piezoelectric-driven optical scanning device

Abstract

This optical scanning device comprises: a substrate; a first cantilever connected to the substrate; a first piezoelectric element disposed on the first cantilever, wherein the first piezoelectric element includes a driving element, which is disposed on the first cantilever and to which voltage is applied, and a sensing element, which is disposed on the first cantilever and generates voltage; a second cantilever connected to the substrate so as to be opposite to the first cantilever; a second piezoelectric element disposed on the second cantilever; a connector connecting the first cantilever to the second cantilever; a reflector for reflecting light; and an elastic body connecting the connector to the reflector.

Description

Piezoelectrically driven optical scanning device

[0001] The disclosure relates to a piezoelectrically driven optical scanning device.

[0002] An optical scanning device is being developed that is configured to reflect light incident from a light source and modulates the direction of the reflected light through rotational motion. U.S. Publication No. US 2010 / 0177370 A1 discloses a scanning display device including a piezoelectric element. The aforementioned background technology was possessed or acquired during the process of deriving the present disclosure and cannot necessarily be considered as publicly known technology disclosed to the general public prior to the filing of the present disclosure.

[0003] One aspect of the disclosure may provide an optical scanning device for increasing the angular displacement of a reflector. One aspect of the disclosure may provide an optical scanning device for measuring / calculating the angular displacement of a reflector.

[0004] An optical scanning device may include a substrate, a first cantilever connected to the substrate, a first piezoelectric element disposed on the first cantilever, the first piezoelectric element including a driving element disposed on the first cantilever and configured to apply a voltage, and a sensing element disposed on the first cantilever and configured to generate a voltage, a second cantilever connected to the substrate opposite to the first cantilever, a second piezoelectric element disposed on the second cantilever, a connector connecting the first cantilever and the second cantilever, a reflector configured to reflect light, and an elastic body connecting the connector and the reflector.

[0005] The above driving element and the above sensing element can be separated from each other.

[0006] The area of ​​the sensing element may be smaller than the area of ​​the driving element.

[0007] The first piezoelectric element may further include an additional driving element disposed on the first cantilever. The sensing element may be disposed between the driving element and the first additional driving element.

[0008] The above driving element and the above sensing element can be arranged in a row.

[0009] The sensing element may be at least partially surrounded by the driving element.

[0010] The above sensing element can be placed on the driving element.

[0011] The size of the sensing element may be the same as the size of the driving element.

[0012] The first cantilever and the second cantilever may be configured to insulate each other from the first piezoelectric element and the second piezoelectric element, respectively. The first cantilever and the second cantilever may further include an insulator disposed on each other.

[0013] The connector may include a plurality of first extensions connected to the first cantilever and the second cantilever, respectively, and extending in a first direction orthogonal to the longitudinal direction of each of the first cantilever and the second cantilever, and a second extension connected to the plurality of first extensions and extending in a second direction parallel to the longitudinal direction of the first cantilever and the second cantilever.

[0014] The connector may include a plurality of first extensions connected to the first cantilever and the second cantilever, respectively, and extending in a direction orthogonal to the respective longitudinal directions of the first cantilever and the second cantilever, a plurality of second extensions connected to the plurality of first extensions and extending in a direction parallel to the respective longitudinal directions of the first cantilever and the second cantilever, a plurality of third extensions connected to the plurality of second extensions and extending in a direction orthogonal to the respective longitudinal directions of the first cantilever and the second cantilever, and a fourth extension connected to the plurality of third extensions and extending in a direction parallel to the respective longitudinal directions of the first cantilever and the second cantilever.

[0015] According to one embodiment, an optical scanning device can increase the degree of design freedom for resonant driving. According to one embodiment, an optical scanning device can drive a reflector substantially without loss of driving force and simultaneously calculate the angular displacement of the reflector. The effects of the optical scanning device according to one embodiment are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0016] The above and other aspects, features and advantages of specific embodiments of the present disclosure will become apparent from the following detailed description with reference to the accompanying drawings.

[0017] FIG. 1A is a plan view of a piezoelectrically driven optical scanning device according to one embodiment.

[0018] FIG. 1b is a cross-sectional view of a piezoelectrically driven optical scanning device according to one embodiment.

[0019] FIG. 1c is a cross-sectional view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0020] FIG. 2 is a plan view of a piezoelectrically driven optical scanning device according to one embodiment.

[0021] FIG. 3 is a plan view of a piezoelectrically driven optical scanning device according to one embodiment.

[0022] FIG. 4 is a plan view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0023] FIG. 5 is a plan view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0024] FIG. 6 is a plan view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0025] FIG. 7 is a plan view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0026] Hereinafter, embodiments are described in detail with reference to the attached drawings. However, the embodiments may be modified in various ways, and the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, or alternatives to the embodiments are included within the scope of the patent application.

[0027] The terms used in the examples are for the purpose of description only and should not be construed as limiting. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, the terms "comprises" or "has" and the like are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but should be understood to not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0028] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the embodiments pertain. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0029] In addition, when describing with reference to the attached drawings, identical components will be assigned the same reference numerals regardless of the drawing numbers, and redundant descriptions thereof will be omitted. When describing embodiments, if a detailed description of a related known technology is judged to unnecessarily obscure the gist of the embodiment, the detailed description will be omitted.

[0030] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of the embodiments. These terms are only intended to distinguish the components from other components, and the nature, order, or sequence of the components are not limited by the terms. When a component is described as being "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but another component may also be "connected," "coupled," or "connected" between each component.

[0031] Components included in one embodiment and components with common functions will be described using the same names in other embodiments. Unless otherwise stated, the descriptions given in one embodiment may also apply to other embodiments, and detailed descriptions will be omitted to the extent of overlap.

[0032] FIG. 1A is a plan view of a piezoelectrically driven optical scanning device according to one embodiment. FIG. 1B is a cross-sectional view of a piezoelectrically driven optical scanning device according to one embodiment. FIG. 1C is a cross-sectional view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0033] Referring to FIGS. 1A to 1C, the optical scanning device (100) may be configured to reflect light (e.g., laser) incident from a light source (e.g., laser light source). The optical scanning device (100) may be configured to modulate or steer the direction of the reflected light.

[0034] The optical scanning device (100) may include a substrate (110). The substrate (110) may include a fixing member configured to fix other components (e.g., a first cantilever (120) and a second cantilever (130)). The substrate (110) may substantially include a polyhedron.

[0035] The optical scanning device (100) may include a first cantilever (120). The first cantilever (120) may be configured to deflect with respect to the substrate (110). The first cantilever (120) may have a first end (e.g., a +Y direction end) connected to a fixed end of the substrate (110) and a second end (e.g., a -Y direction end) opposite thereto. The second end of the first cantilever (120) may be displaced in a direction (e.g., a Z-axis direction) orthogonal to a longitudinal direction (e.g., a -Y direction) of the first cantilever (120). The first cantilever (120) may extend in a longitudinal direction (e.g., a -Y direction) from the fixed end of the substrate (110) (e.g., a fixed end in the +Y direction). In one embodiment, the first cantilever (120) may include a conductive material. For example, the first cantilever (120) may include stainless steel. In one embodiment, the first cantilever (120) may include an insulating material. In one embodiment, the first cantilever (120) may include a semiconductor. For example, the first cantilever (120) may include silicon.

[0036] The optical scanning device (100) may include a second cantilever (130). The second cantilever (130) may be configured to deflect with respect to the substrate (110). The second cantilever (130) may have a third end (e.g., a -Y direction end) connected to a fixed end of the substrate (110) and a fourth end (e.g., a +Y direction end) opposite thereto. The fourth end of the second cantilever (130) may be displaced in a direction (e.g., a Z-axis direction) orthogonal to a longitudinal direction (e.g., a +Y direction) of the second cantilever (130). The second cantilever (130) may extend in a longitudinal direction (e.g., a +Y direction) from the fixed end of the substrate (110) (e.g., a fixed end in the -Y direction). An end face of the second cantilever (130) may face an end face of the first cantilever (120). The first cantilever (120) and the second cantilever (130) may be arranged in one direction (e.g., the Y-axis direction) of the substrate (110). In one embodiment, the second cantilever (130) may include a conductive material. For example, the second cantilever (130) may include stainless steel. In one embodiment, the second cantilever (130) may include an insulating material. For example, the second cantilever (130) may include silicon.

[0037] The optical scanning device (100) may include a first piezoelectric element (140). The first piezoelectric element (140) may include a first electrode (P1) disposed above one surface (e.g., a +Z normal direction surface) of the first piezoelectric element (140) that is oriented in a direction (e.g., a +Z direction) substantially orthogonal to a longitudinal direction (e.g., a Y-axis direction) of the first cantilever (120). The first piezoelectric element (140) may include a second electrode (P2) spaced apart from the first electrode (P1) in one direction (e.g., a +Z direction). The second electrode (P2) may be disposed on the first cantilever (120). The first piezoelectric element (140) may include a piezoelectric material (M) disposed between a first electrode (P1) and a second electrode (P2). The piezoelectric material (M) may be in contact with the first electrode (P1) and the second electrode (P2). The piezoelectric material (M) may include, for example, lead zirconate titanate (PZT). The first piezoelectric element (140) may function as a driving element. For example, when voltage is applied to the first electrode (P1) and the second electrode (P2), the first piezoelectric element (140) may be configured to bend the first cantilever (120). The first piezoelectric element (140) may be disposed on the first cantilever (120). The area of ​​the first piezoelectric element (140) may be substantially equal to or smaller than the area of ​​one side (e.g., the +Z direction side) of the first cantilever (120). For example, the first piezoelectric element (140) may include a bulk piezoelectric plate.

[0038] The optical scanning device (100) may include a second piezoelectric element (150). The structure of the second piezoelectric element (150) may be substantially the same as the structure of the first piezoelectric element (140) illustrated in FIGS. 1A to 1C (e.g., the first electrode (P1), the second electrode (P2), and the piezoelectric material (M)). The second piezoelectric element (150) may function as a driving element. For example, when voltage is applied to the electrodes of the second piezoelectric element (150), the second piezoelectric element (150) may be configured to bend the second cantilever (130). The second piezoelectric element (150) may be disposed on the second cantilever (130). The area of ​​the second piezoelectric element (150) may be substantially equal to or smaller than the area of ​​one side (e.g., the +Z direction side) of the second cantilever (130). For example, the second piezoelectric element (150) may include a bulk piezoelectric plate.

[0039] The optical scanning device (100) may include a plurality of connectors (160). The plurality of connectors (160) may connect the first cantilever (120) and the second cantilever (130). For example, one connector (160) may connect one side of the first cantilever (120) (e.g., the side closer to the -X direction plane) and one side of the second cantilever (130) (e.g., the side closer to the -X direction plane), and another connector (160) may connect the other side of the first cantilever (120) (e.g., the side closer to the +X direction plane) and the other side of the second cantilever (130) (e.g., the side closer to the +X direction plane). A plurality of connectors (160) can extend in one direction (e.g., + / -Y direction) between the first cantilever (120) and the second cantilever (130). When a second end of the first cantilever (120) is displaced in one direction (e.g., +Z direction) and a fourth end of the second cantilever (120) is displaced in the opposite direction (e.g., -Z direction), the plurality of connectors (160) can be bent to form a curved profile (e.g., S profile). Each width of the plurality of connectors (160) can be smaller than a width of the first cantilever (120) (e.g., X direction dimension) and a width of the second cantilever (120) (e.g., X direction dimension).

[0040] The optical scanning device (100) may include a reflector (170). The reflector (170) may reflect light incident on the reflector (170) from a light source (not shown). For example, the reflector (170) may include a mirror. When the first cantilever (120) and the second cantilever (130) are bent, the reflector (170) is configured to rotate about an axis (A2) substantially orthogonal to the longitudinal direction (e.g., Y-axis direction) of each of the first cantilever (120) and the second cantilever (130), thereby modulating or steering the direction of the reflected light. The reflector (170) may have a substantially circular or elliptical cross-section, but is not limited thereto and may also have a polygonal cross-section.

[0041] The optical scanning device (100) may include a holder (172). The holder (172) may support a reflector (170). The holder (172) may at least partially accommodate the reflector (170).

[0042] The optical scanning device (100) may include a plurality of elastic bodies (180). The plurality of elastic bodies (180) may be arranged on an axis A2. One elastic body (180) may connect one connector (160) and one reflector (170), and another elastic body (180) may connect another connector (160) and one reflector (170). The plurality of elastic bodies (180) may be configured to twist about an axis A2.

[0043] In one embodiment, the substrate (110), the first cantilever (120), the second cantilever (130), the connector (160), the holder (172), and the elastic body (180) can be formed seamlessly as one body. In one embodiment, at least one component among the substrate (110), the first cantilever (120), the second cantilever (130), the connector (160), the holder (172), and the elastic body (180) can be manufactured separately from at least one other component and coupled and / or connected to each other.

[0044] The optical scanning device (100) may include an insulator (190). The insulator (190) may insulate the first cantilever (120) from the first piezoelectric element (140) and may insulate the second cantilever (130) from the second piezoelectric element (150). The insulator (190) may be disposed on the first cantilever (120) and the second cantilever (130). The insulator (190) may at least partially surround the first cantilever (120) and the second cantilever (130). At least a portion of the insulator (190) may be disposed between the first cantilever (120) and the first piezoelectric element (140) and between the second cantilever (130) and the second piezoelectric element (150). For example, the insulator (190) may include parylene. In embodiments where the first cantilever (120) and the second cantilever (130) include an insulating material, the optical scanning device (100) may not include the insulator (190).

[0045] The insulator (190) can be created through oxidation of the surface of the first cantilever (120) or the second cantilever (130). For example, if the cantilever (120 or 130) includes aluminum, the insulator (190) can be created by anodizing the surface of the aluminum.

[0046] FIG. 2 is a plan view of a piezoelectrically driven optical scanning device according to one embodiment.

[0047] Referring to FIG. 2, the optical scanning device (200) (e.g., the optical scanning device (100) of FIGS. 1A to 1C) includes a substrate (210) (e.g., the substrate (110) of FIGS. 1A to 1C), a first cantilever (220) (e.g., the first cantilever (120) of FIGS. 1A to 1C), a second cantilever (230) (e.g., the second cantilever (130) of FIGS. 1A to 1C), a first piezoelectric element (240) (e.g., the first piezoelectric element (140) of FIGS. 1A to 1C), a second piezoelectric element (250) (e.g., the second piezoelectric element (150) of FIGS. 1A to 1C), and a plurality of connectors (260) (e.g., the first piezoelectric element (140) of FIGS. 1A to 1C). Connectors (160)), reflectors (270) (e.g., reflectors (170) of FIGS. 1A to 1C), holders (272) (e.g., holders (172) of FIGS. 1A to 1C), and a plurality of elastic bodies (280) (e.g., elastic bodies (180) of FIGS. 1A to 1C).

[0048] Each connector (260) may include a plurality of first extensions (261). One first extension (261) may be connected to a region near one side surface (e.g., + / - X direction surface) from an end surface (e.g., -Y direction surface) of the first cantilever (220), and another first extension (261) may be connected to a region near one side surface (e.g., + / - X direction surface) from an end surface (e.g., +Y direction surface) of the second cantilever (230). The plurality of first extensions (261) may extend in a first direction (e.g., + / - X direction) orthogonal to a longitudinal direction (e.g., -Y direction) of the first cantilever (220).

[0049] Each connector (260) may include a second extension portion (262). The second extension portion (262) may be connected to each end of a plurality of first extension portions (261). The second extension portion (262) may extend in a second direction (e.g., Y-axis direction) parallel to the longitudinal direction (e.g., -Y direction) of the first cantilever (220) and the longitudinal direction (e.g., +Y direction) of the second cantilever (230). The second extension portion (262) may be connected to an elastic body (280).

[0050] The resonant frequency for resonant driving of the reflector (270) can be determined by the relevant parameters (e.g., moment of inertia, elastic coefficient, etc.) of the substrate (210), the first cantilever (220), the second cantilever (230), the connector (260), the holder (272), and the elastic body (280). Since the degree of design freedom of the connector (260) is higher than that of other component(s), changing the shape of the connector (260) as illustrated in FIG. 2 can be advantageous for resonant frequency tuning.

[0051] FIG. 3 is a plan view of a piezoelectrically driven optical scanning device according to one embodiment.

[0052] Referring to FIG. 3, the optical scanning device (300) (e.g., the optical scanning device (100) of FIGS. 1A to 1C) includes a substrate (310) (e.g., the substrate (110) of FIGS. 1A to 1C, and / or the substrate (210) of FIG. 2), a first cantilever (320) (e.g., the first cantilever (120) of FIGS. 1A to 1C, and / or the first cantilever (220) of FIG. 2), a second cantilever (330) (e.g., the second cantilever (130) of FIGS. 1A to 1C, and / or the second cantilever (230) of FIG. 2), a first piezoelectric element (340) (e.g., the first piezoelectric element (140) of FIGS. 1A to 1C, and / or the first piezoelectric element (2) of FIG. The device (240) may include a second piezoelectric element (350) (e.g., the second piezoelectric element (150) of FIGS. 1A to 1C and / or the second piezoelectric element (250) of FIG. 2), a plurality of connectors (360) (e.g., the connector (160) of FIGS. 1A to 1C and / or the connector (260) of FIG. 2), a reflector (370) (e.g., the reflector (170) of FIGS. 1A to 1C and / or the reflector (270) of FIG. 2), a holder (372) (e.g., the holder (172) of FIGS. 1A to 1C and / or the holder (272) of FIG. 2), and a plurality of elastic bodies (380) (e.g., the elastic body (180) of FIGS. 1A to 1C and / or the elastic body (280) of FIG. 2).

[0053] Each connector (360) may include a plurality of first extensions (361). One first extension (361) may be connected to a region near one side surface (e.g., + / - X direction surface) from an end surface (e.g., -Y direction surface) of the first cantilever (320), and another first extension (361) may be connected to a region near one side surface (e.g., + / - X direction surface) from an end surface (e.g., +Y direction surface) of the second cantilever (330). The plurality of first extensions (361) may extend in a first direction (e.g., + / - X direction) orthogonal to a longitudinal direction (e.g., -Y direction) of the first cantilever (320) or a longitudinal direction (e.g., +Y direction) of the second cantilever (320).

[0054] Each connector (360) may include second extensions (362). One second extension (362) may be connected to an end of a first extension (361) connected to a first cantilever (320), and another second extension (362) may be connected to an end of a first extension (361) connected to a second cantilever (330). The plurality of second extensions (362) may extend in a second direction (e.g., Y-axis direction) parallel to a longitudinal direction (e.g., -Y direction) of the first cantilever (320) and a longitudinal direction (e.g., +Y direction) of the second cantilever (330).

[0055] Each connector (360) may include a plurality of third extensions (363). One third extension (363) may be connected to an end of a second extension (362) that is (indirectly) connected to the first cantilever (320), and another third extension (363) may be connected to an end of a second extension (362) that is (indirectly) connected to the second cantilever (330). The plurality of third extensions (363) may extend in a first direction (e.g., + / - X direction).

[0056] Each connector (360) may include a fourth extension (364). The fourth extension (364) may be connected to each end of a plurality of third extensions (363). The fourth extension (364) may extend in a second direction (e.g., in the Y-axis direction). The fourth extension (364) may be connected to an elastic body (380).

[0057] The resonant frequency for resonant driving of the reflector (370) can be determined by the relevant parameters (e.g., moment of inertia, elastic coefficient, etc.) of the substrate (310), the first cantilever (320), the second cantilever (330), the connector (360), the holder (372), and the elastic body (380). Since the degree of design freedom of the connector (360) is higher than that of other component(s), changing the shape of the connector (360) as illustrated in FIG. 3 can be advantageous for resonant frequency tuning.

[0058] FIG. 4 is a plan view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0059] Referring to FIG. 4, an optical scanning device (400) (e.g., an optical scanning device (100) of FIGS. 1A to 1C, an optical scanning device (200) of FIG. 2, and / or an optical scanning device (300) of FIG. 3) includes a substrate (410) (e.g., a substrate (110) of FIGS. 1A to 1C, a substrate (210) of FIG. 2, and / or a substrate (310) of FIG. 3), a cantilever (420) (e.g., a first cantilever (120) and / or a second cantilever (130) of FIGS. 1A to 1C, a first cantilever (220) and / or a second cantilever (230) of FIG. 2, and / or a first cantilever (320) and / or a second cantilever (330) of FIG. 3), and a piezoelectric It may include an element (440) (e.g., the first piezoelectric element (140) and / or the second piezoelectric element (150) of FIGS. 1A to 1C, the first piezoelectric element (240) and / or the second piezoelectric element (250) of FIG. 2, and / or the first piezoelectric element (340) and / or the second piezoelectric element (350) of FIG. 3).

[0060] The piezoelectric element (440) may include a plurality of driving elements (D) configured to receive voltage. When voltage is applied to the plurality of driving elements (D), the cantilever (420) may bend.

[0061] The piezoelectric element (440) may include a sensing element (S) configured to generate a voltage. When the cantilever (420) is bent, the sensing element (S) may generate a voltage. Based on the voltage generated in the sensing element (S), the angular displacement of the reflector (e.g., the reflector (170) of FIGS. 1A to 1C, the reflector (270) of FIG. 2, and / or the reflector (370) of FIG. 3) may be measured by any suitable means (a processor not shown).

[0062] The plurality of driving elements (D) and sensing elements (S) can be separated from each other. For example, the plurality of driving elements (D) and sensing elements (S) can share a single piezoelectric material (e.g., the piezoelectric material (M) of FIGS. 1A to 1C). Each element (D, S) can include a first electrode (e.g., the first electrode (P1) of FIGS. 1A to 1C) and a second electrode (e.g., the second electrode (P2) of FIGS. 1A to 1C). The electrodes of adjacent elements (D, S) can be separated from each other. Such a separation structure can enable both driving and sensing of the piezoelectric element (440) without substantially any loss of driving force. With this separation structure, the angular displacement of the reflector in Fig. 4 can be greater than twice the angular displacement of the reflector when, under the same conditions (e.g., the same voltage), one piezoelectric element arranged on one cantilever is used as a driving element and the other piezoelectric element arranged on the other cantilever is used as a sensing element. Considering that the driving voltage is generally several tens to 100 V or more when driving a piezoelectric, the actual driving loss of the separation structure can be significantly reduced.

[0063] A plurality of driving elements (D) and sensing elements (S) can be arranged in a row in a direction (e.g., X-axis direction) orthogonal to the longitudinal direction (e.g., Y-axis direction) of the cantilever (420). The sensing element (S) can be arranged between the plurality of driving elements (D). The area of ​​the sensing element (S) can be smaller than the area of ​​each of the plurality of driving elements (D). This can enable angular displacement measurement without substantial driving loss.

[0064] In an embodiment not shown, the optical scanning device (400) may include a plurality of piezoelectric elements (440). One piezoelectric element (440) may be disposed on a first side (e.g., a +Z-direction side) of the cantilever (420), and another piezoelectric element (440) may be disposed on a second side (e.g., a -Z-direction side) of the cantilever (420) opposite to the first side. In one example, a separation structure may be applied to all of the plurality of piezoelectric elements (440). In another example, a separation structure (e.g., a structure of multiple electrodes) may be applied to one of the plurality of piezoelectric elements (440), and a non-separated structure (e.g., a structure of a single electrode) may be applied to the other piezoelectric element.

[0065] Meanwhile, this separation structure can be applied to the structure of all piezoelectric elements (440) arranged in each of the cantilevers (420).

[0066] FIG. 5 is a plan view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0067] Referring to FIG. 5, an optical scanning device (500) (e.g., an optical scanning device (100) of FIGS. 1A to 1C, an optical scanning device (200) of FIG. 2, and / or an optical scanning device (300) of FIG. 3) includes a substrate (510) (e.g., a substrate (110) of FIGS. 1A to 1C, a substrate (210) of FIG. 2, and / or a substrate (310) of FIG. 3), a cantilever (520) (e.g., a first cantilever (120) and / or a second cantilever (130) of FIGS. 1A to 1C, a first cantilever (220) and / or a second cantilever (230) of FIG. 2, and / or a first cantilever (320) and / or a second cantilever (330) of FIG. 3), and a piezoelectric It may include an element (540) (e.g., the first piezoelectric element (140) and / or the second piezoelectric element (150) of FIGS. 1A to 1C, the first piezoelectric element (240) and / or the second piezoelectric element (250) of FIG. 2, and / or the first piezoelectric element (340) and / or the second piezoelectric element (350) of FIG. 3).

[0068] The piezoelectric element (540) may include a driving element (D) and a sensing element (S). The driving element (D) and the sensing element (S) may be arranged in a row in a direction (e.g., X-axis direction) orthogonal to the longitudinal direction (e.g., Y-axis direction) of the cantilever (520). The area of ​​the sensing element (S) may be smaller than the area of ​​the driving element (D). This may enable angular displacement measurement without substantial driving loss.

[0069] In an embodiment not shown, the optical scanning device (500) may include a plurality of piezoelectric elements (540). One piezoelectric element (540) may be disposed on a first side (e.g., a +Z-direction side) of the cantilever (520), and another piezoelectric element (540) may be disposed on a second side (e.g., a -Z-direction side) of the cantilever (520) opposite to the first side. In one example, a separation structure may be applied to all of the plurality of piezoelectric elements (540). In another example, a separation structure (e.g., a structure of multiple electrodes) may be applied to one of the plurality of piezoelectric elements (540), and a non-separated structure (e.g., a structure of a single electrode) may be applied to the other piezoelectric element.

[0070] Meanwhile, this separation structure can be applied to the structure of all piezoelectric elements (540) arranged in each of the cantilevers (520).

[0071] FIG. 6 is a plan view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0072] Referring to FIG. 6, an optical scanning device (600) (e.g., an optical scanning device (100) of FIGS. 1A to 1C, an optical scanning device (200) of FIG. 2, and / or an optical scanning device (300) of FIG. 3) includes a substrate (610) (e.g., a substrate (110) of FIGS. 1A to 1C, a substrate (210) of FIG. 2, and / or a substrate (310) of FIG. 3), a cantilever (620) (e.g., a first cantilever (120) and / or a second cantilever (130) of FIGS. 1A to 1C, a first cantilever (220) and / or a second cantilever (230) of FIG. 2, and / or a first cantilever (320) and / or a second cantilever (330) of FIG. 3), and a piezoelectric It may include an element (640) (e.g., the first piezoelectric element (140) and / or the second piezoelectric element (150) of FIGS. 1A to 1C, the first piezoelectric element (240) and / or the second piezoelectric element (250) of FIG. 2, and / or the first piezoelectric element (340) and / or the second piezoelectric element (350) of FIG. 3).

[0073] The piezoelectric element (640) may include a driving element (D) and a sensing element (S). The sensing element (S) may be at least partially surrounded by the driving element (D). For example, except for one side surface (e.g., a +Y direction surface) of the sensing element (S), the remaining three side surfaces (e.g., a + / -X direction surface and a -Y direction surface) may be surrounded by the driving element (D). The area of ​​the sensing element (S) may be smaller than the area of ​​the driving element (D). This may enable angular displacement measurement without substantial driving loss.

[0074] In an embodiment not shown, the optical scanning device (600) may include a plurality of piezoelectric elements (640). One piezoelectric element (640) may be disposed on a first side (e.g., a +Z-direction side) of the cantilever (620), and another piezoelectric element (640) may be disposed on a second side (e.g., a -Z-direction side) of the cantilever (620) opposite to the first side. In one example, a separation structure may be applied to all of the plurality of piezoelectric elements (640). In another example, a separation structure (e.g., a structure of multiple electrodes) may be applied to one of the plurality of piezoelectric elements (640), and a non-separated structure (e.g., a structure of a single electrode) may be applied to the other piezoelectric element.

[0075] Meanwhile, this separation structure can be applied to the structure of all piezoelectric elements (640) arranged in each of the cantilevers (620).

[0076] FIG. 7 is a plan view of a portion of a piezoelectrically driven optical scanning device according to one embodiment.

[0077] Referring to FIG. 7, an optical scanning device (700) (e.g., an optical scanning device (100) of FIGS. 1A to 1C, an optical scanning device (200) of FIG. 2, and / or an optical scanning device (300) of FIG. 3) includes a substrate (710) (e.g., a substrate (110) of FIGS. 1A to 1C, a substrate (210) of FIG. 2, and / or a substrate (310) of FIG. 3), a cantilever (720) (e.g., a first cantilever (120) and / or a second cantilever (130) of FIGS. 1A to 1C, a first cantilever (220) and / or a second cantilever (230) of FIG. 2, and / or a first cantilever (320) and / or a second cantilever (330) of FIG. 3), a piezoelectric It may include an element (740) (e.g., the first piezoelectric element (140) and / or the second piezoelectric element (150) of FIGS. 1A to 1C, the first piezoelectric element (240) and / or the second piezoelectric element (250) of FIG. 2, and / or the first piezoelectric element (340) and / or the second piezoelectric element (350) of FIG. 3), and an insulator (790) (e.g., the insulator (190) of FIGS. 1A to 1C).

[0078] The piezoelectric element (740) may include a first electrode (P1), a second electrode (P2) spaced apart from the first electrode (P1) in one direction (e.g., in the -Z direction) and disposed on a cantilever (720) or on an insulator (790), a first piezoelectric material (M1) disposed between the first electrode (P1) and the second electrode (P2), a third electrode (P3) spaced apart from the first electrode (P1) in the opposite direction (e.g., in the +Z direction), and a second piezoelectric material (M2) disposed between the first electrode (P1) and the third electrode (P3).

[0079] The piezoelectric element (740) may include a driving element (D) and a sensing element (S). The driving element (D) may be disposed on the cantilever (720) or on the insulator (790), and the sensing element (S) may be disposed on the driving element (D). The first electrode (P1), the second electrode (P2), and the first piezoelectric material (M1) may define the driving element (D), and the first electrode (P1), the third electrode (P3), and the second piezoelectric material (M2) may define the sensing element (S).

[0080] The area of ​​the sensing element (S) may be substantially equal to or smaller than the area of ​​the driving element (D). The area of ​​the second electrode (P2) may be substantially equal to or smaller than the area of ​​the first electrode (P1). The area of ​​the third electrode (P3) may be substantially equal to or smaller than the area of ​​the first electrode (P1). The area of ​​the second piezoelectric material (M2) may be substantially equal to or smaller than the area of ​​the first piezoelectric material (M1).

[0081] The laminated structure of the piezoelectric element (740) described in FIG. 7 can enable both driving and sensing of the piezoelectric element (740) substantially without loss of driving force. With this laminated structure, the optical scanning device (700) of FIG. 7 can substantially prevent loss of driving force, unlike a case where, under the same conditions (e.g., the same voltage), one piezoelectric element disposed on one cantilever is used as a driving element and another piezoelectric element disposed on another cantilever is used as a sensing element.

[0082] Meanwhile, this laminated structure can be applied to the structure of all piezoelectric elements (740) arranged in each of the cantilevers (620).

[0083] Although the embodiments described above have been described with limited drawings, those skilled in the art will appreciate that various technical modifications and variations can be applied based on the above. For example, appropriate results can still be achieved even if the described techniques are performed in a different order than described, and / or components of the described systems, structures, devices, circuits, etc. are combined or combined in a different manner than described, or are replaced or substituted with other components or equivalents.

[0084] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims described below.

Claims

1. Substrate, a first cantilever connected to the above substrate; A first piezoelectric element disposed on the first cantilever, wherein the first piezoelectric element comprises a driving element disposed on the first cantilever and configured to apply voltage, and a sensing element disposed on the first cantilever and configured to generate voltage. a second cantilever connected to the substrate opposite to the first cantilever; A second piezoelectric element arranged on the second cantilever, A connector connecting the first cantilever and the second cantilever, a reflector configured to reflect light, and Elastic body connecting the above connector and the above reflector An optical scanning device comprising:

2. In paragraph 1, The above driving element and the above sensing element are an optical scanning device separated from each other.

3. In paragraph 1, An optical scanning device wherein the area of ​​the sensing element is smaller than the area of ​​the driving element.

4. In paragraph 1, An optical scanning device wherein the first piezoelectric element further comprises an additional driving element disposed on the first cantilever, and the sensing element is disposed between the driving element and the additional driving element.

5. In paragraph 1, An optical scanning device in which the driving element and the sensing element are arranged in a row.

6. In paragraph 1, An optical scanning device wherein the sensing element is at least partially surrounded by the driving element.

7. In paragraph 1, The above sensing element is an optical scanning device arranged on the above driving element.

8. In paragraph 7, An optical scanning device wherein the size of the sensing element is the same as the size of the driving element.

9. In paragraph 1, An optical scanning device further comprising an insulator disposed on the first cantilever and the second cantilever, the insulator configured to insulate the first cantilever and the second cantilever from the first piezoelectric element and the second piezoelectric element, respectively.

10. In paragraph 1, The above connector, A plurality of first extension portions each connected to the first cantilever and the second cantilever and extending in a first direction orthogonal to the respective longitudinal directions of the first cantilever and the second cantilever, and A second extension connected to the plurality of first extensions and extending in a second direction parallel to the longitudinal direction of the first cantilever and the second cantilever An optical scanning device comprising:

11. In paragraph 1, The above connector, A plurality of first extension portions each connected to the first cantilever and the second cantilever and extending in a direction orthogonal to the respective longitudinal directions of the first cantilever and the second cantilever, A plurality of second extensions connected to the plurality of first extensions and extending in a direction parallel to the longitudinal direction of each of the first cantilever and the second cantilever, A plurality of third extensions connected to the plurality of second extensions and extending in a direction orthogonal to the longitudinal direction of each of the first cantilever and the second cantilever, and A fourth extension connected to a plurality of third extensions and extending in a direction parallel to the longitudinal direction of each of the first cantilever and the second cantilever. An optical scanning device comprising:

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