Mirror driving device for lidar scanner

Abstract

The present invention relates to a lidar mirror driving device for driving a mirror included in a lidar device. The present invention comprises: a rotor unit including a coil and a shaft so as to rotate; a stator unit including a stator housing, and a magnet and a bearing arranged on the stator housing; a mirror and an encoder unit coupled to the rotor unit; and a circuit unit coupled to the stator unit. The encoder unit stores at least one piece of position information, angle information and speed information of the mirror, and the circuit unit generates a driving signal on the basis of the stored information. The stator unit and the rotor unit generate an electromagnetic force according to the driving signal, and a shaft rotates by means of the electromagnetic force so as to rotate the mirror. The present invention has an effect of increasing the degree of design freedom of the lidar scanner.

Description

Mirror drive unit for LiDAR scanner

[0001] The present invention relates to a mirror driving device for a LiDAR scanner that drives a mirror to scan a specific range.

[0002] Conventional LiDAR scanners are devices that collect information about the surrounding environment by reflecting lasers and reconstruct it in 3D, and they are utilized in various fields. To scan the surrounding environment, a LiDAR scanner requires an encoder, a mirror, and a drive unit, and the drive unit can be composed of a stator and a rotor. However, in conventional LiDAR scanners, increasing the size of the mirror can lead to an increase in the overall size of the scanner, which may result in a problem where the design freedom of the scanner system is limited. Specifically, in the structure of conventional scanner devices, the mirror must be fixed at the end of the rotation axis; therefore, the scanner size increases depending on the mirror size, leading to low space efficiency. Furthermore, in other conventional LiDAR scanner structures, the drive unit and encoder are attached to both ends of the mirror, causing the overall length of the scanner to increase depending on the mirror size. Additionally, in conventional LiDAR scanner devices, there is a time delay during the current switching process of the coil required to change the mirror's direction of operation. This results in non-uniform mirror operation speeds, causing differences in scanning speeds within the VFOV range. These factors impose limitations on the design and performance of existing LiDAR scanners.

[0003] In conventional LiDAR scanners, the mirror is often fixed at the very end of the rotation axis, or the drive unit and encoder are attached to both ends of the mirror. In this case, as the size of the mirror increases, the overall size of the LiDAR scanner increases, leading to design limitations; therefore, this invention aims to resolve these limitations.

[0004] Furthermore, the power of conventional LiDAR scanners originates from the interaction between coils and magnets, and switching the direction of current is required to change the operating direction of the mirror. Since this causes a time delay in changing the mirror's operating direction and impairs LiDAR scanner performance, this invention aims to resolve these issues.

[0005] In addition, there was a problem where the lubricant in the bearing coupled to the rotation axis was rapidly consumed when conventional LiDAR scanners rotated, and this invention aims to solve this problem.

[0006] In addition, we aim to minimize performance variations between LiDAR scanner products and reduce product costs.

[0007] In addition, we aim to reduce the equipment investment costs of the LiDAR scanner and facilitate process management.

[0008] In addition, we aim to reduce manufacturing costs through the simple assembly structure of the LiDAR scanner.

[0009] A lidar mirror driving device according to the present invention for achieving the above objective comprises: a rotor part including a coil and a shaft configured to rotate around its own longitudinal axis; a stator part including a stator housing, a magnet spaced apart from the coil and disposed in the stator housing, a bearing groove formed in the stator housing, and a bearing coupled to the shaft and fixed in the bearing groove; a mirror coupled to the rotor part; an encoder part coupled to the rotor part; and a circuit part coupled to the stator part. The encoder part is configured to store at least one of position information, angle information, and speed information of the mirror, and the circuit part is configured to generate a driving signal based on the stored information. The stator part and the rotor part are configured to generate an electromagnetic force based on the generated driving signal, and the shaft may be configured to rotate by the electromagnetic force and to rotate the mirror connected to the shaft.

[0010] Additionally, the rotor part of the lidar mirror driving device further includes a mirror holder coupled to the mirror and the encoder part; and a coil holder coupled to the coil and the mirror holder; wherein the shaft is coupled to the coil holder while passing through an opening formed in the coil holder, and the mirror holder may further include an inclined surface formed along the direction of the rotation axis of the shaft.

[0011] Additionally, in the above-described lidar mirror driving device, the stator housing is composed of a first stator housing and a second stator housing, the magnet is composed of a first magnet and a second magnet, the first magnet is disposed in a first magnet groove formed inside the first stator housing, the second magnet is disposed in a second magnet groove formed inside the second stator housing, the bearing is composed of a first bearing and a second bearing, the first bearing is fixed in a first bearing groove formed inside the first stator housing, the second bearing is fixed in a second bearing groove formed inside the second stator housing, the rotor part is located between the first stator housing and the second stator housing, the first bearing is coupled to one end of the shaft, and the second bearing can be coupled to the opposite end of the shaft.

[0012] Additionally, the lidar mirror driving device further includes a first recess formed in the first magnet and a second recess formed in the second magnet, wherein the first bearing groove is formed spaced apart from the boundary line of the part where the first recess and the first stator housing contact, and the second bearing groove can be formed spaced apart from the boundary line of the part where the second recess and the second stator housing contact.

[0013] Additionally, the lidar mirror driving device further includes a first assembly surface formed on the first stator housing and a second assembly surface formed on the second stator housing, and the first stator housing and the second stator housing are joined such that the first assembly surface and the second assembly surface face each other, so that an air gap can be formed between the first magnet, the second magnet, and the coil.

[0014] In addition, the lidar mirror driving device further includes a first step formed between the first assembly surface and the first magnetic groove and a second step formed between the second assembly surface and the second magnetic groove, and the first step and the second step may be coupled facing each other to form a coil groove.

[0015] Additionally, the lidar mirror driving device may further include at least one screw opening formed when the first stator housing and the second stator housing are joined facing each other with respect to the assembly surface; and at least one fixing screw coupled to the screw opening.

[0016] In addition, the lidar mirror driving device comprises a spring coupled to the shaft; and

[0017] It further includes a spring fixing part formed in the mirror holder; wherein one end of the spring contacts the first stator housing or the second stator housing, and the other end of the spring can be fixed to the spring fixing part.

[0018] Additionally, in the lidar mirror driving device, the encoder unit further includes an encoder disk; and the circuit unit further includes an encoder IC; and the encoder disk may be physically coupled to the rotor unit, and the encoder IC may be physically coupled to the stator unit.

[0019] In the present invention, the rotor part can be surrounded by the stator part, and the wide surface of the mirror can be designed to face the LiDAR scanner device. This solves the scanner size issue caused by the increase in mirror size, thereby increasing design freedom and improving space efficiency.

[0020] In addition, by attaching a spring to the shaft and securing both ends of the spring to the stator and rotor, the current switching delay occurring when the mirror operation direction is changed is reduced, thereby effectively maintaining a uniform scanning speed in the VFOV range.

[0021] In addition, by designing the two stator housings to be joined with their assembly surfaces facing each other, performance variations between products are minimized, and manufacturing costs are reduced.

[0022] Furthermore, the simple assembly structure using fixed screws reduces equipment investment costs and facilitates process management. In addition, the support structure provides robustness against external vibrations and shocks.

[0023] In addition, by directly combining the encoder IC in the stator and the encoder disk in the rotor, there is an effect of reducing manufacturing costs and facilitating assembly position management. Furthermore, there is an effect of increasing the precision of the encoder configuration and improving data measurement accuracy.

[0024] In summary, the present invention provides the effect of improving the design, manufacturing efficiency, reliability, etc. of a lidar scanner.

[0025] FIG. 1 is a cross-sectional view showing the internal structure of a mirror driving device for a LiDAR scanner according to one embodiment of the present invention.

[0026] FIG. 2 is an exploded perspective view showing the state before some components are assembled in a mirror driving device for a lidar scanner according to one embodiment of the present invention.

[0027] FIG. 3(a) is a perspective view showing a mirror driving device for a LiDAR scanner in a completed state according to one embodiment of the present invention.

[0028] Figure 3(b) is a diagram illustrating the Vertical Field of View (VFOV), which is the field of view that can be observed by the mirror driving device for the lidar scanner.

[0029] FIG. 4 is an exploded perspective view showing the main components of a mirror driving device for a LiDAR scanner in an exploded state according to one embodiment of the present invention.

[0030] FIG. 5(a) is a cross-sectional view showing the air gap between the coil and the magnet in a mirror driving device for a lidar scanner according to one embodiment of the present invention.

[0031] FIG. 5(b) is a cross-sectional view showing the assembly surface that comes into contact when two stator housings are combined in a mirror driving device for a lidar scanner according to one embodiment of the present invention.

[0032] FIG. 6 is an exploded perspective view showing the combination of a rotor assembly and a stator assembly in a mirror driving device for a lidar scanner according to one embodiment of the present invention.

[0033] FIG. 7 is a perspective view showing that a spring is connected to a rotor and a stator in a mirror driving device for a lidar scanner according to one embodiment of the present invention.

[0034] FIG. 8 is a perspective view showing that some components of a mirror driving device for a lidar scanner according to one embodiment of the present invention are combined in a different way with the mirror driving device for a lidar scanner.

[0035] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components are given the same reference number regardless of the drawing symbols, and redundant descriptions thereof will be omitted.

[0036] In addition, when describing the embodiments disclosed in this specification, if it is determined that a detailed description of related prior art may obscure the essence of the embodiments disclosed in this specification, such detailed description is omitted. Furthermore, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that the drawings include all modifications, equivalents, and substitutions that fall within the spirit and technical scope of the invention.

[0037] FIG. 1 is a cross-sectional view showing the internal structure of a mirror driving device (10) for a lidar scanner according to one embodiment of the present invention.

[0038] According to one embodiment of the present invention, a mirror driving device (10) for a LiDAR scanner may include a mirror (120), an encoder unit (100), a circuit unit (200), a rotor unit (300), and a stator unit (400). A LiDAR device using a LiDAR mirror driving device may be a vertical scanner, but is not limited thereto. A vertical scanner can scan the surroundings by repeatedly moving up and down a specific section, and the specific section is called a VFOV (Vertical Field of View).

[0039] According to one embodiment of the present invention, the encoder unit (100) can perform the function of transmitting information such as the position and angle of the mirror (120) in the mirror driving device (10) for the LiDAR scanner. Specifically, the encoder unit (100) may include an encoder holder (110) and an encoder disk (105) attached to the encoder holder (110). The encoder disk (105) can measure and store information such as the current position, angle, and speed of the mirror (120). At this time, the information of the mirror (120) measured and stored by the encoder disk (105) can be transmitted to the encoder IC (210) of the circuit unit (200). Meanwhile, the encoder unit (100) can be implemented in the form of an optical encoder, a magnetic encoder, a capacitive encoder, an absolute encoder, an incremental encoder, etc.

[0040] According to one embodiment of the present invention, a mirror (120) can reflect a laser beam as part of a process of scanning a specific area of ​​the surrounding environment. At this time, the material of the mirror (120) may be selected considering high reflectivity, lightness, durability, etc. Specifically, the mirror (120) may be manufactured based on glass, metal, plastic, ceramic, or multilayer coated mirror, such as tempered glass, silica glass, aluminum, copper, metal alloy, polycarbonate, acrylic, silicone, etc. Additionally, the mirror (120) may be combined with a mirror holder (130). Furthermore, an encoder holder (110) to which an encoder disk (105) is attached may be combined with the mirror holder (130) together with a guide pin (111) to be connected to the mirror (120). Additionally, the mirror holder (130) may be combined with a coil holder (340) described later, and accordingly, the mirror (120) and the coil (320) described later may be connected. With the above combination, the rotor part (300) rotates by the force generated by the coil (320), and the mirror (120) and encoder (105) connected to the rotor part (300) can rotate in conjunction. Meanwhile, the encoder holder (110) and the mirror holder (130) are not essential components for implementing the present invention, and the mirror (120) and the encoder part (100) may be directly connected to the rotor part (300) without holders.

[0041] According to one embodiment of the present invention, the circuit unit (200) receives a signal containing at least one of position information, angle information, and speed information from the encoder unit (100) and processes the received signal to generate a signal for driving the rotor unit (300). Specifically, the circuit unit (200) can calculate the position, speed, and angle of the mirror (120) in real time based on a signal containing information of the mirror (120) and adjust the signal for driving the rotor unit (300). More specifically, according to the driving signal generated by the circuit unit (200), a current in a certain direction flows through the coil (320), and the coil (320) and the magnet (420) interact to rotate and swivel the rotor unit (300) up and down. Additionally, the circuit unit (200) may include an encoder IC (210), and the encoder IC (210) may be manufactured through a PCBA (Printed Circuit Board Assembly) process. Additionally, the circuit portion (200) can be coupled to the stator portion (400).

[0042] According to one embodiment of the present invention, the rotor part (300) may include a bearing (310), a spring (330), and a shaft (350). The rotor part (300) can generate power to rotate the mirror (120) in the mirror driving device (10) for the LiDAR scanner and can transmit the power to the mirror (120). Specifically, the rotor part (300) can rotate the shaft (350) with a force generated by the interaction between the coil (320) and the magnet (420) of the stator part (400), and can control the position and angle of the mirror (120), encoder disk (105), etc., which are indirectly connected to the shaft (350), in real time. At this time, the bearing (310) can be fixed in a bearing groove (311) formed in the stator part (400) and coupled with the shaft (350). In addition, the spring (330) can be coupled with the shaft (350). The shaft (350) is coupled with the bearing (310) to enable rotation, and is indirectly connected to the mirror (120) so that the rotational force of the shaft (350) can be transmitted to the mirror (120). Meanwhile, in this embodiment, the bearing (310) belongs to the rotor part (300), but it may also be included in the stator part (400). Details of each component of the rotor part (300) will be described later.

[0043] According to one embodiment of the present invention, the stator (400) interacts with the rotor (300) to contribute to the generation of electromagnetic force, which is the power of the rotor (300), and can induce rotation of the shaft (350). In addition, the stator (400) can mechanically fix the mirror driving device (10) for the lidar scanner to induce stable movement. Furthermore, the distance between the stator (400) and the rotor (300) can be maintained at a constant level, thereby maximizing magnetic efficiency and optimizing movement performance. Meanwhile, the stator (400) may include a magnet (420) and a stator housing (430), and details of each component will be described later.

[0044] FIG. 2 is an exploded perspective view showing the state before some components are assembled in a mirror driving device for a lidar scanner according to one embodiment of the present invention.

[0045] As described, the encoder holder (110) to which the encoder disk (105) is coupled can be coupled to the mirror holder (130) coupled to the rotor part (300). Additionally, the mirror (120) can be coupled to the mirror holder (130) coupled to the rotor part (300). Additionally, the circuit part (200) can be coupled to the stator housing (430), which is part of the stator part (400). Additionally, the rotor part (300) and the stator part (400) can be coupled in such a way that the stator part (400) surrounds the rotor part (300). At this time, the fixing screw (410) can be coupled to a plurality of stator housings (430a, 430b) divided to surround the rotor part (300), and accordingly, the mirror driving device (10) for the LiDAR scanner can be firmly assembled.

[0046] Meanwhile, an inclined surface (131) may be formed on a part of the outer surface of the mirror holder (130). Specifically, the inclined surface (131) of the mirror holder (130) may be formed obliquely along the direction of the rotation axis of the shaft (350). This structure can prevent contact with other components when the mirror holder (130) rotates. That is, the structure of the inclined surface (131) of the mirror holder (130) enables a wide VFOV range (20) of the mirror driving device (10) for the LiDAR scanner. Meanwhile, the inclined surface (131) of the mirror holder (130) may be combined with a spring (330) described later.

[0047] FIG. 3(a) is a drawing for showing a completed state of a mirror driving device (10) for a LiDAR scanner according to one embodiment of the present invention. As shown, the rotor part (300) surrounds the stator part (400), and the mirror holder (130) coupled with the rotor part (300) can be coupled with the mirror (120). Accordingly, within the size limit of the mirror driving device (10) for a LiDAR scanner, the size of the mirror (120) can be varied, and thus a degree of freedom in the design of the mirror driving device (10) for a LiDAR scanner is created.

[0048] FIG. 3(b) is a drawing for illustrating the Vertical Field of View (VFOV) that can be observed by the mirror driving device (10) for the lidar scanner. As shown, the rotor (300) and the mirror (120) can scan the surroundings while rotating and turning in the VFOV section (20).

[0049] FIG. 4 is an exploded perspective view showing the main components of a mirror driving device (10) for a lidar scanner in an exploded state according to one embodiment of the present invention. As described above, the mirror driving device (10) for a lidar scanner may include a mirror (120), an encoder unit (100), a circuit unit (200), a rotor unit (300), and a stator unit (400), and the details of each component are as follows.

[0050] According to one embodiment of the present invention, in a mirror driving device (10) for a LiDAR scanner, the encoder unit (100) may include an encoder disk (105) and an encoder holder (110). The encoder disk (105) may be coupled with the encoder holder (110) and may transmit information regarding the precise position and motion state of the mirror (120) to the circuit unit (200). Additionally, the encoder disk (105) may be implemented with a material such as an optical, magnetic, or capacitive type.

[0051] Additionally, the encoder holder (110) can secure the encoder disk (105) in the mirror drive device (10) for the lidar scanner. Through this, the encoder disk (105) can be stably supported and maintain a constant position. Specifically, the encoder holder (110) can be coupled with the mirror holder (130) by securing the guide pin (111). However, the encoder holder (110) is not a necessary component, and it is also possible for the encoder disk (105) to be directly coupled to the rotor part (300) or the mirror holder (130).

[0052] According to one embodiment of the present invention, the circuit section (200) of the mirror driving device (10) for a LiDAR scanner may include an encoder IC (210). The encoder IC (210) can detect the movement of the encoder disk (105) and, based on this, can calculate the position, speed, etc. of the mirror (120). In addition, the encoder IC (210) can generate a driving signal based on the information of the mirror (120). The current direction of the coil (320) can be determined according to the generated driving signal, and accordingly, the rotor section (300) can rotate in the VFOV (20) section. Meanwhile, the encoder IC (210) can be implemented based on optical, magnetic, or capacitive technology and can be designed in the form of a single chip through a PCBA process. In addition, the encoder section (200) including the encoder IC (210) can be combined with one of two stator housings (430a, 430b).

[0053] According to one embodiment of the present invention, in a mirror driving device (10) for a LiDAR scanner, the rotor part (300) may include a mirror holder (130), a bearing (310), a coil (320), a spring (330), a coil holder (340), and a shaft (350). First, the bearing (310) may be fixed to a stator housing (430) and coupled with the shaft (350) to enable the shaft (350) to perform rotational movement. At this time, the bearing (310) may perform the function of minimizing friction with the shaft (350) to rotate the shaft (350) smoothly. Additionally, the bearing (310) may be composed of a first bearing (310a) fixed to a first stator housing (430a) and a second bearing (310b) fixed to a second stator housing (430b). At this time, the first bearing (310a) and the second bearing (310b) can each be coupled to both ends of the shaft (350) to assist in the rotation of the rotor part (300). That is, the first bearing (310a) can be coupled to one end of the shaft (350), and the second bearing (310b) can be coupled to the opposite end of the shaft (350). Meanwhile, in this embodiment, the bearing (310) belongs to the rotor part (300), but it may also be included in the stator part (400).

[0054] Additionally, the coil (320) can be coupled with the coil holder (340), and accordingly, the shaft (350) coupled with the coil holder (340) can be indirectly connected to the coil (320). Additionally, the mirror holder (130) can be coupled with the coil holder (340), and the mirror (120) coupled with the mirror holder (130) can be indirectly connected to the coil (320). Additionally, the encoder unit (100) coupled with the mirror holder (130) can be indirectly connected to the coil (320). Furthermore, the coil (320) can be positioned at a certain distance from the magnet (420) fixed to the stator unit (400). At this time, the coil (320) can interact with the magnet (420) to induce rotation of the shaft (350). Specifically, when a current of a certain direction and strength flows through the coil (320), the shaft (350) rotates due to the electromagnetic force induced by the coil (320) and the magnet (420), and accordingly, the rotor part (300) can rotate.

[0055] Meanwhile, in conventional lidar devices, coils often contain a core. When a core is included in a coil, it can amplify the magnetic field to generate a large force. However, in conventional lidar devices containing a core, even if the current direction of the coil is switched for direction change, the magnetic field amplified by the core may not disappear and may remain; this is called the phenomenon of magnetic hysteresis. The presence of such a residual magnetic field can delay the direction change of the lidar device, which can have an adverse effect on the scanning performance of the lidar device. In contrast, in one embodiment of the present invention, the coil (320) does not contain a core, so less residual magnetic field may be generated compared to the case where a core is included. Accordingly, the direction change of the mirror driving device (10) for the lidar scanner is not delayed, and the scanning speed can be maintained at a constant level.

[0056] Additionally, the spring (330) can be coupled such that both ends of the spring (330) are fixed to the rotor (300) and the stator (400), respectively, and the middle part of the spring is wound around the shaft (350). In this case, the spring (330) can provide a restoring force to return the axis of rotation to a neutral position after the shaft (350) has rotated. Specifically, to change the rotational direction of the mirror drive device (10) for the LiDAR scanner, current direction switching of the coil (320) is required. At this time, a slight time delay inevitably occurs for current direction switching, and this problem occurs at the upper and lower boundaries of the VFOV section (20) where the mirror drive device (10) for the LiDAR scanner changes direction. In this case, the spring (330) can provide a restoring force in the direction that the rotor (300) intends to change direction from before the current direction switching of the coil (320). Accordingly, the mirror drive device (10) for the lidar scanner can scan at a constant speed over the entire VFOV section (20). Meanwhile, although the shaft (350) is circular in shape in the drawing, it is not limited thereto and may be polygonal in shape as a means to effectively transmit the elastic force of the spring (330) to the shaft (350).

[0057] Additionally, the coil holder (340) can be combined with the coil (320) to support the coil (320) and can be combined with the shaft (350) and the mirror holder (130). An opening may be formed in the coil holder (340), and the shaft (350) may pass through the opening. That is, the shaft (350) can be combined with the coil holder (340) while passing through the opening of the coil holder (340). Through such combination, energy generated from the coil (320) is transmitted to the shaft (350) through the coil holder (340), and as the shaft (350) rotates, the mirror (120) connected to the shaft (350) can also rotate. Meanwhile, the coil holder (340) can be positioned at the center of the shaft (350) by being penetrated by the shaft (350). Additionally, the first stator housing (430a) and the second stator housing (430b) can be combined with both ends of the shaft to surround the rotor part (300).

[0058] Additionally, the shaft (350) can be connected to the stator part (400) by being coupled with the bearing (310), can be coupled to the coil holder (340) by passing through the opening of the coil holder (340), and can be connected to the rotor part (300) and the stator part (400) by being coupled with the spring (330). As a result, the shaft (350) rotates by receiving the force generated by the coil (320) and can rotate the encoder part (100) including the encoder disk (105) and the mirror (120).

[0059] According to one embodiment of the present invention, in a mirror driving device (10) for a LiDAR scanner, the stator part (400) may include a fixing screw (410), a magnet (420), and a stator housing (430). First, the fixing screw (410) may be coupled with the stator housing (430) and may fix the mirror driving device (10) for a LiDAR scanner including the rotor part (300). Specifically, there may be multiple fixing screws (410). Additionally, the fixing screw (410) may be coupled with at least one screw opening formed when the first stator housing (430a) and the second stator housing (430b) are coupled facing each other. The screw opening may be formed when the assembly surface (450) of the first stator housing (430a) and the second stator housing (430b) come into contact.

[0060] Additionally, the stator housing (430) can be combined with a bearing (310) and a magnet (420). There may be two stator housings (430), such as a first stator housing (430a) and a second stator housing (430b). The stator housing (430) can serve as the entire frame of the stator part (400). Additionally, a magnet groove (431) may be formed inside the stator housing (430), and a magnet (420) may be placed in the magnet groove (431). Additionally, a bearing groove (311) may be formed inside the stator housing (430), and a bearing (310) may be placed in the bearing groove (311).

[0061] Specifically, when the magnet (420) is placed in the magnet groove (431) of the stator housing (430), the magnet (420) can be spaced apart from the coil (320) to maintain a constant air gap (460). The magnet (420) can interact with the coil (320) to induce rotation of the shaft (350) by force through electromagnetic induction. The number of magnets (420) may be multiple, half of which may be placed in the first magnet groove (431a) of the first stator housing (430a), and the other half of which may be placed in the second magnet groove (431b) of the second stator housing (430b).

[0062] Additionally, a first bearing (310a) may be fixed in a first bearing groove (311a) formed in a first stator housing (430a), and a second bearing (310b) may be fixed in a second bearing groove (311b) formed in a second stator housing (430b). Meanwhile, conventionally, the bearing was often coupled to an opening and the lidar device rotated along the axis. However, according to one embodiment of the present invention, the bearing (310) may be fixed in a bearing groove (311) that is closed on one side. This structure has a sealing effect, which can prevent the loss of lubricant applied to the bearing (310). Furthermore, since the lubricant can remain in the bearing (310) for a longer period, friction and wear of the bearing (310) can be effectively reduced.

[0063] According to one embodiment of the present invention, a first stator housing (430a) and a second stator housing (430b) can be joined while facing each other symmetrically. Specifically, a rotor part (300) is positioned between the first stator housing (430a) and the second stator housing (430b), and both ends of the shaft (350) of the rotor part (300) can be joined to a first bearing (310a) fixed to the first stator housing (430a) and a second bearing (310b) fixed to the second stator housing (430b), respectively. Additionally, the first stator housing (430a) and the second stator housing (430b) can be assembled by being fixed by a fixing screw (410) after coming into contact. Additionally, a rotor part (300) surrounded by a stator part (400) is coupled with a mirror holder (130), and the mirror holder (130) and the mirror (120) can be coupled.

[0064] Due to the above combination, the opposite side of the reflective surface of the mirror (120) may face the surface of the mirror driving device (10) for the LiDAR scanner that is combined with the mirror (120). That is, the opposite side of the reflective surface of the mirror (120) may face the surface where the mirror driving device (10) for the LiDAR scanner and the mirror (120) are combined. Accordingly, the problem of the overall size of the mirror driving device (10) for the LiDAR scanner becoming excessively large depending on the size of the mirror (120) can be resolved.

[0065] FIG. 5(a) is a cross-sectional view showing an air gap, i.e., an air gap (460), between a coil (320) and a magnet (420) in a mirror driving device (10) for a lidar scanner according to one embodiment of the present invention. FIG. 5(b) is a cross-sectional view showing an assembly surface (450) that comes into contact when two stator housings (430a, 430b) are combined in a mirror driving device (10) for a lidar scanner according to one embodiment of the present invention. As illustrated, the stator part (400) may include two identical stator housings (430a, 430b), and an assembly surface (450) may be formed on each stator housing (430a, 430b). At this time, the respective assembly surfaces (450) of the first stator housing (430a) and the second stator housing (430b) may be combined facing each other to form a part of the stator part (400). Specifically, the first assembly surface (450) formed on the first stator housing (430a) and the second assembly surface (450) formed on the second stator housing (430b) can be joined while facing each other.

[0066] Meanwhile, in order for electromagnetic force to be generated through an electromagnetic induction reaction, the coil (320) and the magnet (420) must be spaced apart. At this time, the magnet (420) and the coil (320) placed inside the first stator housing (430a) and the second stator housing (430b) can maintain a constant and uniform air gap (460), and as a result, the performance variation of each product can be minimized. In addition, the air gap (460) can effectively transmit the magnetic field of the magnet (420) to the coil (320). By utilizing this, the same performance can be expected even if the size of the magnet and the number of turns of the coil are reduced, and the cost of the product can be reduced. In addition, the assembly surface (450) can be formed through precision machining, and precise dimensional control of the air gap (460) becomes possible.

[0067] According to one embodiment of the present invention, a step (432) may be formed in the stator housing (430). Specifically, a stepped step may be formed, and the step (432) may be formed between the assembly surface (450) and the magnet groove (431). In this case, when the first stator housing (430a) and the second stator housing (430b) are combined, the respective steps (432) may face each other and be combined, and as a result, a coil groove (433) may be formed. Specifically, the first step (432) formed in the first stator housing (430a) and the second step (432) formed in the second stator housing (430b) may face each other and be combined to form the coil groove (433). When the coil groove (433) is formed, a clearance space may be created between the coil (320) and the stator part (400). As a result, the coil groove (433) can extend the VFOV range (20) when the rotor part (300) rotates.

[0068] FIG. 6 is an exploded perspective view showing the combination of a rotor assembly (3000) and a stator assembly (4000a, 4000b) in a mirror driving device (10) for a lidar scanner according to one embodiment of the present invention.

[0069] According to one embodiment of the present invention, each stator assembly (4000a, 4000b) may include a bearing (310), a magnet (420), and a stator housing (430). Additionally, the first stator assembly (4000a) may include a first stator housing (430a), and the second stator assembly (4000b) may include a second stator housing (430b). Additionally, the rotor assembly (3000) may include a rotor part (300) including a shaft (350) and a coil (420), and a mirror holder (130). Additionally, although not shown in FIG. 6, a mirror (120) may be coupled to the mirror holder (130) of the rotor assembly (3000). Additionally, the first stator assembly (4000a) and the second stator assembly (4000b) may be coupled while facing each other symmetrically. Specifically, the rotor assembly (3000) is positioned between the first stator assembly (4000a) and the second stator assembly (4000b), and both ends of the shaft (350) of the rotor assembly (3000) can be coupled to the first bearing (310a) fixed to the first stator assembly (4000a) and the second bearing (310b) fixed to the second stator assembly (4000b), respectively. Additionally, the first stator assembly (4000a) and the second stator assembly (4000b) can be assembled by one or more fixing screws (410) after coming into contact with each other.

[0070] As described above, when the first stator assembly (4000a) and the second stator assembly (4000b) are combined in a symmetrical structure, assembly is simple, which can reduce equipment investment costs and facilitate process management. Additionally, the support structure provided by the bearings (310) on both sides helps maintain the balance of the shaft (350) and is excellent against external vibration and shock conditions, thereby extending the lifespan of the product. Furthermore, the stable combination of the rotor assembly (3000) and the stator assembly (4000) minimizes performance deviations, thereby increasing the reliability of the product.

[0071] Additionally, the mirror (120) can be coupled with the mirror holder (130) of the rotor assembly (3000) combined with the stator assembly (4000a, 4000b). Due to such coupling, the opposite side of the reflective surface of the mirror (120) can face one side of the mirror driving device (10) for the LiDAR scanner. That is, the opposite side of the reflective surface of the mirror (120) can face one side of the mirror driving device (10) for the LiDAR scanner where the mirror holder (130) and the mirror (120) are coupled. Accordingly, the problem of the overall size of the mirror driving device (10) for the LiDAR scanner becoming excessively large as the size of the mirror (120) increases can be resolved.

[0072] Additionally, according to one embodiment of the present invention, a recess may be formed in the magnet (420) in which a specific portion is reduced or removed. In this case, the bearing groove (311) may be formed at a location spaced apart from the boundary line of the portion where the recess of the magnet (420) and the stator housing (430) come into contact. The structure of the recess and the bearing groove (311) prevents physical interference between the bearing (310) and the magnet (420). Specifically, the magnet (420) may be placed in the magnet groove (431) of the stator housing (430), and the bearing (310) may be placed in the free space of the magnet groove (431) formed by the recess. That is, the shaft (350), magnet (420), and coil (320) components may be densely arranged with minimized spacing between them. This dense arrangement structure created by the recess enables the efficient transmission of electromagnetic force. In addition, the volume of the stator housing (430) can be minimized, and a compact design of the mirror drive device (10) for the lidar scanner is possible.

[0073] FIG. 7 is a perspective view showing that a spring (330) is connected to a rotor part (300) and a stator part (400) in a mirror driving device (10) for a lidar scanner according to one embodiment of the present invention.

[0074] According to one embodiment of the present invention, a first spring fixing part (331) may be formed in the stator housing (430) of the stator part (400). Additionally, a second spring fixing part (332) may be formed in the mirror holder (130). Specifically, the first spring fixing part (331) and the second spring fixing part (332) may be in the form of grooves, and are not necessarily limited to the form of grooves as a configuration for fixing the spring (330). For example, the spring (330) may be fixed by means of a fixing pin, clip fixing, adhesive fixing, bracket fixing, screw fixing, rivet fixing, slot fixing, ring fixing, etc., and may be appropriately selected to implement the present invention. At this time, both ends of the spring (330) may be fixed to the first spring fixing part (331) and the second spring fixing part (332), respectively. Specifically, one end of the spring (330) is fixed to the first spring fixing part (331), and the other end of the spring (330) is fixed to the second spring fixing part (332), and the spring (330) can be wound and coupled to the shaft (350). Meanwhile, the spring (330) may be composed of two or more springs, and the first spring fixing part (331) and the second spring fixing part (332) may also be formed in multiple numbers. In this case, half of the multiple springs (330) may be placed on one side relative to the center of the shaft (350), and the other half of the springs (330) may be placed on the opposite side relative to the center of the shaft (350).

[0075] In another embodiment, the first spring fixing part (331) may not be formed in the stator housing (430), and one end of the spring (330) may be fixed by contacting the surface of the stator part (400). Here, being fixed does not mean that one end of the spring (330) must always be in contact with the stator part (400). The spring (330) is configured to transmit a restoring force to the mirror driving device (10) for the lidar scanner as the shaft (350) rotates. Accordingly, depending on the design method, one end of the spring (330) may be separated from the stator part (400) during the operation of the mirror driving device (10) for the lidar scanner. In addition, as one embodiment, the shape of the second spring fixing part (332) may be formed as an L-shaped groove. In this case, the end of the spring (330) can be pushed in after being inserted into the L-shaped groove formed in the mirror holder (130), and the spring (330) can be fixed to the mirror holder (130).

[0076] Meanwhile, conventional LiDAR devices have a problem in that a time delay occurs during the process of changing the direction of the current flowing through the coil when the direction of motion is changed. Accordingly, an imbalance in scanning speed occurs at the top and bottom of the VFOV section (20), and a deviation in data quality may occur. However, according to one embodiment of the present invention, the elastic force of the spring (330) can be applied during the process in which the direction changes while the mirror (120) operates in the up and down direction. This elastic force acts as a restoring force at the maximum angle of the VFOV section (20) when the mirror driving device (10) for the LiDAR scanner is operated, thereby minimizing the time delay that occurs during the change of the coil's current direction. In this case, the first spring fixing part (331) and the second spring fixing part (332) can help the spring (330) transmit the restoring force more effectively. Through this, the response speed of the mirror driving device (10) for the LiDAR scanner can be increased, and accuracy and reliability can be improved.

[0077] FIG. 8 is a perspective view showing that some components of a mirror driving device (10) for a lidar scanner according to one embodiment of the present invention are combined in a different way with the mirror driving device (10) for a lidar scanner.

[0078] According to one embodiment of the present invention, the circuit section (200) can be directly (physically) coupled to the stator section (400), and the encoder section (100) can be directly (physically) coupled to the rotor section (300) or the mirror holder (130). Specifically, in the circuit section (200), a circuit board containing an encoder IC (210) can be directly (physically) coupled to the stator section (400) without a separate fixing device. In addition, in the encoder section (100), the encoder disk (105) can be directly (physically) coupled to the rotor section (300) or the mirror holder (130) without an intermediate mechanism such as an encoder holder (110).

[0079] According to this embodiment, the cost can be reduced by manufacturing with a simple combined structure rather than a separate assembly. In addition, the assembly position management of the encoder IC (210) and the encoder disk (105) becomes easier, and the accuracy of the mirror driving device (10) for the lidar scanner can be improved.

[0080] [Explanation of the symbol]

[0081] 10 Mirror drive unit for LiDAR scanner

[0082] 20 VFOV sections

[0083] 100 encoder section

[0084] 105 encoder disk

[0085] 110 Encoder Holder

[0086] 111 guide pin

[0087] 120 mirrors

[0088] 130 Mirror Holder

[0089] 131 Slope

[0090] 200 circuit section

[0091] 210 Encoder IC

[0092] 300 rotor part

[0093] 310 Bearings (310a, 310b)

[0094] 311 Bearing groove (311a, 311b)

[0095] 320 coil

[0096] 330 springs

[0097] 331 First spring fixing part

[0098] 332 Second spring fixing part

[0099] 340 coil holder

[0100] 350 shaft

[0101] 400 fixed parts

[0102] 410 fixing screw

[0103] 420 Magnet (420a, 420b)

[0104] 430 Stator housing (430a, 430b)

[0105] 431 Magnetic Home

[0106] 432 Step

[0107] 433 Coil Home

[0108] 440 guide pin

[0109] 450 assembly surface

[0110] 460 voids

[0111] 2000 circuit board

[0112] 3000 rotor assembly

[0113] 4000 Stator Assembly (4000a, 4000b)

Claims

1. A lidar mirror driving device for driving a mirror disposed within a lidar device, A rotor part comprising a coil and a shaft configured to rotate around its own longitudinal axis; A stator part comprising a stator housing, a magnet spaced apart from the coil and disposed in the stator housing, a bearing groove formed in the stator housing, and a bearing coupled to the shaft and fixed in the bearing groove; A mirror coupled to the rotor part above; An encoder part coupled to the rotor part above; and A circuit part coupled to the above-mentioned stator part; including, The encoder unit is configured to store at least one of position information, angle information, and velocity information of the mirror, and The above circuit is configured to generate a driving signal based on the stored information, and The stator and rotor are configured to generate electromagnetic force based on the generated driving signal, and The shaft is configured to rotate by the electromagnetic force and to rotate the mirror connected to the shaft. LiDAR mirror drive unit.

2. In Paragraph 1, The above rotor part is, A mirror holder coupled to the above mirror and the above encoder unit; and It further includes a coil holder coupled to the above coil and the above mirror holder, The above shaft passes through an opening formed in the coil holder and is coupled with the coil holder, and The above mirror holder further includes an inclined surface formed along the direction of the rotation axis of the shaft, LiDAR mirror drive unit.

3. In Paragraph 2, The above stator housing is composed of a first stator housing and a second stator housing, and The above magnet is composed of a first magnet and a second magnet, and The first magnet is disposed in a first magnet groove formed inside the first stator housing, and the second magnet is disposed in a second magnet groove formed inside the second stator housing. The above bearing is composed of a first bearing and a second bearing, and The first bearing is fixed in a first bearing groove formed inside the first stator housing, and the second bearing is fixed in a second bearing groove formed inside the second stator housing. The rotor part is located between the first stator housing and the second stator housing, and The first bearing is coupled to one end of the shaft, and the second bearing is coupled to the opposite end of the shaft. LiDAR mirror drive unit.

4. In Paragraph 3, It further includes a first recess formed in the first magnet and a second recess formed in the second magnet, The first bearing groove is formed spaced apart from the boundary line of the portion where the first recess and the first stator housing contact each other, and The second bearing groove is formed spaced apart from the boundary line of the portion where the second recess and the second stator housing contact each other. LiDAR mirror drive unit.

5. In Paragraph 4, It further includes a first assembly surface formed on the first stator housing and a second assembly surface formed on the second stator housing, and The first stator housing and the second stator housing are joined such that the first assembly surface and the second assembly surface face each other, thereby forming an air gap between the first magnet, the second magnet, and the coil. LiDAR mirror drive unit.

6. In Paragraph 5, It further includes a first step formed between the first assembly surface and the first magnet groove and a second step formed between the second assembly surface and the second magnet groove, The first step and the second step face each other and are joined to form a coil groove. LiDAR mirror drive unit.

7. In Paragraph 6, At least one screw opening formed when the first stator housing and the second stator housing are joined facing each other with respect to the assembly surface; and further comprising at least one fixing screw coupled to the screw opening above, LiDAR mirror drive unit.

8. In Paragraph 7, A spring coupled to the above shaft; and It further includes a spring fixing part formed in the mirror holder above, and One end of the spring contacts the first stator housing or the second stator housing, and the other end of the spring is fixed to the spring fixing part. LiDAR mirror drive unit.

9. In Paragraph 8, The above encoder unit further includes an encoder disk, and The above circuit further includes an encoder IC, and The encoder disk is physically coupled to the rotor part, and The above encoder IC is physically coupled to the stator part, LiDAR mirror drive unit.

Images