Lens holding mechanism, optical device, control system, and mobile device

Abstract

To provide a lens holding mechanism capable of pressing a lens in an optical axis direction while suppressing deformation such as twist or kinking of an elastic member.SOLUTION: Disclosed is a lens holding mechanism which holds a lens and includes: a lens barrel for housing the lens: a holding member which is fitted to the lens barrel and presses the lens in a direction along an optical axis; and an elastic member arranged between the lens and the holding member. An engaging part is formed in the holding member, and an engaged part which is engaged with the engaging part in a radial direction or a circumferential direction is formed in the lens.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a lens holding mechanism, an optical device, a control system, and a moving device. [Background technology]

[0002] Optical devices installed in vehicles such as automobiles include, for example, cameras that capture images of the vehicle's surroundings and sensors that perform driving assistance and autonomous driving functions. Another optical device with a sensing function is LiDAR (Light Detection and Ranging).

[0003] These devices have a lens barrel that holds the optical element. When an optical element is held in a lens barrel, the difference in the amount of expansion and contraction caused by the difference in the linear expansion coefficient between the optical element and the lens barrel can cause a gap (backlash) in the optical axis direction when the ambient temperature changes. This backlash can cause the holding position to change, which can lead to deterioration of optical performance and deterioration of parts over time. In-vehicle cameras, LiDAR, and other devices are required to guarantee excellent performance and functionality across the entire temperature range of a wide range of changing temperature environments.

[0004] Furthermore, in-vehicle cameras usually do not include an autofocus mechanism for cost reasons. In contrast, there is a configuration in which a circular elastic member is sandwiched between the pressing ring and the optical element, and is compressed by a required amount beforehand during assembly at room temperature to provide elasticity and eliminate play at high temperatures. Automotive driver assistance and autonomous driving functions will require even higher performance and functionality than today, and it is expected that the optical systems of in-vehicle cameras, which act as the eyes of the car, will need to become even more complex and sophisticated.

[0005] As the optical system of an in-vehicle camera becomes more complex and sophisticated, the number of optical elements also increases, which may lead to greater play in the press ring, lens barrel, optical element, etc. caused by temperature changes. Furthermore, for example, when an optical device is externally mounted on a vehicle, an elastic member may also be used to provide water resistance and waterproofing in rainy weather. Patent Document 1 discloses a configuration in which both the press ring and the elastic member hold the optical element in a state in which they can come into contact with the optical element. Patent Document 2 discloses a configuration in which the optical element is held by the press ring via the elastic member. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6192560 [Patent Document 2] Japanese Patent Application Publication No. 05-127058 Summary of the Invention [Problem to be solved by the invention]

[0007] However, with the configurations in Patent Documents 1 and 2, when the presser ring is rotated and screwed in during assembly, friction between the elastic member, the presser ring, and the optical element can cause the elastic member to deform, such as twisting or kinking. If the elastic member is held in a deformed state, the force holding the optical element in the lens barrel by the presser ring will not be applied evenly, which can lead to a deterioration in assembly precision, such as tilting the optical element, and thus a deterioration in optical performance.

[0008] Furthermore, if the environmental temperature changes while the elastic member is deformed, and components such as the lens barrel and optical elements expand and contract according to the linear expansion coefficient of their respective materials, the amount of deformation of the elastic member relative to the resulting play and the amount of release from crushing will differ in some areas, which could result in further degradation of optical performance when the environmental temperature changes.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a lens holding mechanism that is capable of pressing a lens in the optical axis direction while suppressing deformation such as twisting or kinking of an elastic member, for example. [Means for solving the problem]

[0010] In order to achieve the above object, one aspect of the present invention is a lens holding mechanism that holds a lens, and is characterized in that it has a lens barrel that stores the lens, a holding member that fits into the lens barrel and presses the lens in a direction along the optical axis, and an elastic member that is arranged between the lens and the holding member, and in that an engaging portion is formed on the holding member, and an engaged portion that engages with the engaging portion in the radial or circumferential direction is formed on the lens. [Effects of the Invention]

[0011] According to the present invention, for example, it is possible to provide a lens holding mechanism that can press a lens in the optical axis direction while suppressing deformation such as twisting or kinking of an elastic member. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view of an imaging device according to a first embodiment. [Figure 2] 2 is an example of an exploded perspective view illustrating the optical element, the elastic member, and the holding member of FIG. 1. [Figure 3] 2 is a cross-sectional view showing an example in which the shapes of the optical element and the holding member in FIG. 1 are modified. [Figure 4] FIG. 10 is a cross-sectional view showing an example of a lens module according to a second embodiment. [Figure 5] FIG. 10 is an exploded perspective view showing an example of an optical element, an elastic member, and a holding member according to Example 2. [Figure 6] FIG. 10 is a configuration diagram of an in-vehicle system according to a third embodiment. [Figure 7] FIG. 11 is a schematic diagram of a vehicle as a moving device including an in-vehicle system according to a third embodiment. [Figure 8] 10 is a flowchart illustrating an example of the operation of the in-vehicle system according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, the same members or elements are designated by the same reference numerals, and duplicated descriptions will be omitted or simplified.

[0014] Example 1 Fig. 1 shows a schematic cross-sectional view of an optical device 1 according to Example 1. Fig. 2 is an example of an exploded perspective view of a first optical element 5, a holding member 7, and an elastic member 8 according to Example 1. The optical device 1 according to Example 1 will be described below with reference to Figs. 1 and 2.

[0015] The optical device 1 of Example 1 includes a lens module 2, a housing 3, an electrical device (not shown), and a control unit (not shown). It also includes a perforated mirror, a fixed mirror, a movable mirror, a condensing lens, a light receiving element, a light source forming unit (light projecting unit), and the like, all of which are not shown. For example, if the optical device 1 is an in-vehicle camera, the lens module 2 functions as an imaging optical system, and a signal is input to an electrical device (not shown) including an image sensor, thereby acquiring environmental information about the surroundings of the vehicle. The acquired information is used, for example, in driving assistance or autonomous driving systems.

[0016] The lens module 2 has a lens barrel 4, a first optical element 5, other optical systems 6, a holding member 7, and an elastic member 8. The holding member 7 holds the first optical element 5 and other optical systems 6, inside which a spacer (not shown) is arranged, to the lens barrel 4. The lens module 2 is held in a housing 3.

[0017] The housing 3 houses a perforated mirror, a fixed mirror, a movable mirror, a condensing lens, a light receiving element, a light source forming unit (light projecting unit), etc., all of which are not shown. The perforated mirror (light guiding unit) is a mirror that is fixedly held in the housing 3 and has a hole (opening). The perforated mirror can transmit illumination light (e.g., laser light) through the hole and reflect it from its reflective surface. The perforated mirror guides illumination light from the light source forming unit to the fixed mirror and guides reflected light from the fixed mirror to the condensing lens. The fixed mirror is a mirror that is fixedly held in the housing 3. The fixed mirror guides illumination light from the perforated mirror to the movable mirror and guides reflected light from the movable mirror to the perforated mirror.

[0018] The movable mirror (deflection unit, scanning unit) is a mirror that is fixedly held in the housing 3 and scans an object using illumination light from the light source forming unit. The movable mirror may be configured as a two-axis driven mirror, and for example, a MEMS (Micro Electro Mechanical System) mirror or the like can be used. The movable mirror irradiates the illumination light from the fixed mirror onto a target area via optical elements (first optical element 5 and other optical systems 6), and also guides reflected light from an object in the target area to the fixed mirror via the optical elements.

[0019] The condenser lens is an optical element (condensing optical system) that is fixedly held in the housing 3 and condenses the illumination light from the perforated mirror and guides the condensed illumination light to the light receiving element. The light receiving element is an element that photoelectrically converts the illumination light from the light source forming unit and outputs a signal. As the light receiving element, a PD (Photo Diode), APD (Avalanche Photo Diode), SPAD (Single Photon Avalanche Diode), etc. are used. The perforated mirror, fixed mirror, movable mirror, condenser lens, light receiving element, etc. are incorporated into the housing 3 and are stored within the housing 3.

[0020] The light source forming unit (light projecting unit) has a light source unit (semiconductor laser), a convergent lens, and a fixed aperture. The light source is a light source that emits illumination light. The convergent lens is an optical element that adjusts the shape (beam shape) of the illumination light from the light source unit in the target irradiation area. The fixed aperture is configured to block unnecessary light contained in the illumination light emitted from the light source via the convergent lens, and the light is projected from the opening.

[0021] The lens barrel 4 has a male thread portion 4a and a support portion 4b, and houses the first optical element 5 and other optical systems 6. The lens barrel 4 of Example 1 is made of metal or resin material. The male thread portion 4a is a thread portion formed along the outer periphery of a part of the cylindrical or conical outer surface of the lens barrel 4. The support portion 4b is a surface perpendicular to the optical axis (a surface perpendicular to the optical axis) facing one side surface of the other optical systems 6 in the optical axis direction, and supports the first optical element 5 and other optical systems 6. Note that the support portion 4b is not limited to a surface perpendicular to the optical axis, but may be an inclined surface.

[0022] The first optical element (lens) 5 has a protrusion receiving portion (engaged portion) 5a. In Example 1, the protrusion receiving portion 5a is configured to have a flat surface (flat portion) on the outer diameter portion (outer periphery side in the direction perpendicular to the optical axis) of the first optical element 5. In Example 1, one protrusion receiving portion 5a is provided on the first optical element 5, but if multiple protrusions 7a (described later) are formed, multiple protrusion receiving portions 5a may be formed accordingly. In addition, the first optical element 5 is configured as a convex lens. However, the first optical element 5 is not limited to this, and may be configured in the shape of a concave lens, an aspherical lens, or the like. The first optical element 5 is configured from a transparent member such as glass or a resin material.

[0023] The holding member 7 has a protrusion (engagement portion) 7a and a female screw portion 7b. The protrusion 7a is formed to protrude a predetermined length in the optical axis direction and is configured to have a flat surface (flat portion) at a position where it will abut (engage) with the flat portion of the protrusion receiver 5a when the lens module 2 is assembled. The length of the protrusion 7a in the optical axis direction is configured to be a length that does not protrude beyond the end of the first optical element 5 on the other optical system 6 side when the lens module 2 is assembled. Therefore, the length by which the protrusion 7a protrudes in the optical axis direction can be arbitrary as long as it does not protrude beyond the end of the first optical element 5 on the other optical system 6 side and can abut against the protrusion receiver 5a by an appropriate length.

[0024] In the first embodiment, one protrusion 7a is provided on the holding member 7, but this is not limiting and two or more protrusions may be formed. In this case, the protrusion receiving portions 5a are formed on the first optical element 5 according to the number and positions of the protrusions 7a. Note that although the protrusion receiving portion 5a is in radial contact (engagement) with the protrusion 7a in FIGS. 1 and 2, there may be a slight gap between the protrusion receiving portion 5a and the protrusion 7a in the radial direction. In other words, it is sufficient that the protrusion 7a and the protrusion receiving portion 5a are engaged in the radial or circumferential direction.

[0025] The female thread portion 7b is a thread formed along the inner circumference of part of the cylindrical or conical inner surface of the holding member 7. When the male thread portion 4a shown in FIG. 1 and the female thread portion 7b are threadedly engaged, the holding member 7 is fitted into the lens barrel 4 and fixed thereto.

[0026] The holding member 7 also has an annular groove in which the elastic member 8 is disposed. The groove of the holding member 7 is formed in the holding member 7 so as to be closer to the inner periphery in the direction perpendicular to the optical axis than the surface of the protrusion 7a described above, as shown in Fig. 2. The groove of the holding member 7 is configured so that the cross-sectional diameter of the elastic member 8 in the direction perpendicular to the optical axis (radial direction) is approximately the same as the dimension in the radial direction.

[0027] The groove of the holding member 7 holds the elastic member 8 by sandwiching it so that the installation position of the elastic member 8 does not shift (move) or come off, for example, when assembling the optical device 1 or the lens module 2. The groove may be, for example, a recess (including a concave shape and a shape equivalent to a concave shape) or a semicircular shape, and any shape is acceptable as long as the position of the elastic member 8 does not shift when the elastic member 8 is placed. Furthermore, the groove may be provided on the first optical element 5 side, in which case the holding member 7 may not have a groove. The holding member 7 of Example 1 is made of metal or a resin material.

[0028] The elastic member 8 is made of a rubber material such as silicone rubber and is integrally formed in an annular (ring) shape. Because the elastic member 8 is formed in an integral annular shape, when it comes into contact with the periphery of the first optical element 5, it comes into contact over the entire circumference. While the elastic member 8 is preferably formed in an integral annular shape as described above, for example, the elastic member 8 may be configured in an annular shape that comes into contact with a portion of the first optical element 5, or may be configured from three elastic members that come into contact with the first optical element 5 at predetermined intervals, such as 120 degree intervals. The elastic member 8 is held by being sandwiched between the first optical element 5 and the holding member 7 when the lens module 2 is assembled.

[0029] The control unit (not shown) is configured by at least one computer including a CPU, memory (storage unit), etc., and is connected to each component of the optical device 1 via a line. The control unit also performs overall control of the operation adjustment of each component of the entire optical device 1 in accordance with a computer program stored in the memory. This controls the operation of the flowchart in FIG. 8, which will be described later. For example, the control unit is preferably configured integrally with other parts of the optical device 1 (for example, inside the housing 3), but may also be configured separately from other parts of the optical device 1.

[0030] Furthermore, a control unit (not shown) controls the light source unit, the movable mirror, the light receiving element, etc. Specifically, the light source unit and the movable mirror are driven at predetermined drive voltages and drive frequencies, respectively, and the light receiving waveform when the light receiving element receives light is measured at a specific frequency. The control unit then measures the difference between the light receiving time obtained by the light receiving element and the light emission time of the light source unit, or the difference between the phase of the light receiving signal obtained by the light receiving element and the phase of the output signal from the light source unit, and multiplies the difference by the speed of light to determine the distance to the target.

[0031] Next, the procedure (steps) for holding the first optical element 5 and the other optical systems 6 in the lens barrel 4 will be described. First, the elastic member 8 is inserted into the groove of the holding member 7 so as to be sandwiched between them, and the elastic member 8 is held by the holding member 7. Next, the other optical systems 6 are inserted into the lens barrel 4. Next, the first optical element 5 is inserted, and the flat surface of the protrusion receiving portion 5a of the first optical element 5 is brought into contact with the flat surface of the protrusion 7a of the holding member 7.

[0032] Thereafter, the female thread portion 7b of the holding member 7 is screwed into the male thread portion 4a of the barrel 4, whereby the flat portion of the protrusion 7a and the flat portion of the protrusion receiving portion 5a are in contact (engage) with each other in the direction perpendicular to the optical axis (radial direction), thereby fixing the holding member 7 and the barrel 4. As a result, the first optical element 5, holding member 7, and elastic member 8 rotate together when rotated in the rotational direction (circumferential direction) around the optical axis.

[0033] With the above configuration, the elastic member 8 can be held in a state where twisting or torsional deformation of the elastic member 8 that may occur due to friction between the first optical element 5, with which the elastic member 8 is in contact, and the holding member 7 is suppressed. This allows the holding member 7 to hold (press) the peripheral portion of the first optical element 5 with a uniform force via the elastic member 8.

[0034] In Example 1, for example, the lens barrel 4, the holding member 7, and the spacer (not shown) are made of an aluminum alloy with a linear expansion coefficient of 26×10^-6 / °C. The first optical element 5 and the other optical system 6 are made of a glass material with a linear expansion coefficient of 7×10^-6 / °C.

[0035] Here, as an example, it is assumed that there is one spacer with a thickness of 5 mm in the other optical system 6, and the distance in the optical axis direction from the receiving portion of the R1 surface of the first optical element 5 to the support portion 4b of the lens barrel 4 is 25 mm. The receiving portion of the R1 surface of the first optical element 5 is the portion of the first optical element 5 that comes into contact with the elastic member 8.

[0036] At this time, a temperature change of 1°C causes a thermal expansion difference of approximately 0.29 μm between the receiving portion of the R1 surface of the first optical element 5 and the support portion 4b of the lens barrel 4. That is, a difference in the distance between the lens barrel 4 and the first optical element 5 of approximately 0.29 μm occurs. For example, when the optical device 1 is placed in an external environment such as outdoors, and the ambient temperature and the temperature inside the device are 60°C higher than when the optical device 1 is assembled, a play (play amount) of approximately 17.4 μm occurs in the optical axis direction. Furthermore, in an environment where the ambient temperature is 60°C lower than when the optical device 1 is assembled, as described above, a lens (optical element) deformation of approximately 17.4 μm occurs in the optical axis direction.

[0037] In Example 1, the above-described backlash in the optical axis direction is absorbed by elastic deformation of the elastic member 8, which is disposed in the groove of the holding member 7 and comes into contact with the first optical element 5 to press the first optical element 5 in the optical axis direction. That is, in an environment where the outside air temperature rises or falls by 60°C from the temperature at the time of assembly of the optical device 1, etc., as described above, the length of the optical element in the optical axis direction changes by approximately 11.4 μm, but the amount of deformation of the optical element at this time can be absorbed by the elastic member 8.

[0038] Furthermore, by integrally holding the elastic member 8 so that the first optical element 5, the holding member 7, and the elastic member 8 are rotatable around the optical axis, it is possible to suppress twisting or torsional deformation of the elastic member 8 that may occur due to friction, etc. In Example 1, as described above, the surface of the protrusion receiving portion 5a that abuts against the planar surface of the protrusion 7a is also planar, so that each can be easily processed into a shape. However, the shapes of the protrusion receiving portion 5a and the protrusion 7a are not limited to this, and may be, for example, shapes such as those shown in FIG.

[0039] Fig. 3 is an exploded perspective view of the holding member 27, the elastic member 28, and the first optical element 25. The parts shown in Fig. 3 differ from the parts shown in Figs. 1 and 2 in that the shapes of the protrusions and protrusion receivers are different, and therefore explanations of parts that overlap with those explained above will be omitted.

[0040] As shown in Fig. 3, the protrusion (engagement portion) 27a of the holding member 27 is formed so that the cross section in the direction perpendicular to the optical axis is rectangular. Furthermore, the protrusion 27a is formed so as to protrude a predetermined length in the optical axis direction. Furthermore, the protrusion receiving portion 25a of the first optical element 25 is formed in a shape corresponding to the protrusion 27a on the first optical element 25. For example, the protrusion receiving portion 25a in the example of Fig. 3 is formed so that the cross section in the direction perpendicular to the optical axis is concave.

[0041] In addition, in Fig. 3, the radial cross-sectional shape of the protrusion 27a is rectangular, but it may be a shape other than rectangular, such as a triangular or trapezoidal shape. In this case, the protrusion receiving portion 25a has a shape corresponding to the shape of the protrusion 27a. In addition, in Fig. 3, the protrusion receiving portion 25a abuts (engages) with the protrusion 27a in the radial direction, but the depth of the groove in the protrusion receiving portion 25a may be deeper than the thickness of the protrusion 27a. In other words, it is sufficient that the protrusion 27a and the protrusion receiving portion 25a engage with each other in the radial or circumferential direction.

[0042] As described above, in the optical device 1 of Example 1, the first optical element 5 (25), the holding member 7 (27), and the elastic member 8 (28) rotate together, so that the elastic member 8 can be held in a state where twisting or torsional deformation of the elastic member 8 is suppressed. This makes it possible to provide an optical device 1 that can hold the first optical element 5 by applying a uniform force by the holding member 7 via the elastic member 8.

[0043] Furthermore, although the optical device 1 in the first embodiment is assumed to be applied to an in-vehicle camera used for driving assistance or autonomous driving, the present invention is not limited to this and may be applied to an optical device for an in-vehicle camera.

[0044] <Example 2> In Example 1, an example was described in which a protrusion receiving portion 5a having a shape corresponding to the shape of the protrusion 7a is provided on the outer diameter portion of the optical element (first optical element 5). In Example 2, a lens module (lens holding mechanism) in which a protrusion receiving portion is provided on a portion other than the outer diameter portion of the optical element (first optical element 5) will be described. Note that matters not mentioned in Example 2 follow Example 1.

[0045] Fig. 4 is a cross-sectional view illustrating a lens module 22 according to Example 2. Fig. 5 is an example of an exploded perspective view of a first optical element 35, a holding member 37, and an elastic member 38 according to Example 2.

[0046] In Example 2, the first optical element 35 is configured as a resin-molded lens. Furthermore, the holding member 37 is configured from a resin-molded component. By configuring the first optical element 35 and the holding member 37 from resin-molded components, the manufacturing costs or component costs of the first optical element 35 and the holding member 37 can be reduced, and it becomes possible to process them into a shape with a high degree of freedom during processing, etc.

[0047] The lens barrel 34 has a female screw portion 34a and a support portion 34b. The lens barrel 4 of Example 2 is made of metal or resin material. The female screw portion 34a is a screw portion formed along the inner circumference of a part of the cylindrical or conical inner surface of the lens barrel 34. The support portion 34b is a surface perpendicular to the optical axis (a surface perpendicular to the optical axis) facing one side surface of the other optical system 36 in the optical axis direction, and supports the first optical element 35 and the other optical system 36. Note that the support portion 34b is not limited to a surface perpendicular to the optical axis, but may be an inclined surface.

[0048] The first optical element 35 has a protrusion receiving portion (engaged portion) 35a. The protrusion receiving portion 35a is provided between the outside of the effective diameter of the first optical element 35 and the inside of the outer diameter. The protrusion receiving portion 35a is configured to have a shape corresponding to the protrusion portion 37a, and in Example 2, the cross section perpendicular to the optical axis is formed to be circular. The protrusion receiving portion 35a is configured as a hole portion having a size that allows the protrusion portion 37a to be inserted when assembling the lens module 22. In the example shown in FIG. 5, the first optical element 35 is provided with three protrusion portions 37a, but this is not limited thereto and at least one or more protrusion portions 37a may be formed. The protrusion receiving portion 35a is formed according to the number and positions of the protrusions 37a. It is preferable that the number of protrusion receiving portions 35a is the same as the number of protrusions 37a, but it is also possible to form more protrusion receiving portions 35a than the number of protrusions 37a.

[0049] The holding member 37 has a protrusion (engagement portion) 37a and a male screw portion 37b. The protrusion 37a has a circular cross section perpendicular to the optical axis and is formed to protrude a predetermined length in the optical axis direction. That is, the protrusion 37a in Example 2 is formed in a cylindrical shape as shown in FIG. 5.

[0050] The length of the protrusion 37a in the optical axis direction is set to a length that does not protrude beyond the end of the first optical element 35 on the side of the other optical system 36 when the lens module 22 is assembled. Therefore, the length of the protrusion 37a in the optical axis direction can be any length as long as it does not protrude beyond the end of the first optical element 35 on the side of the other optical system 36. Note that the protrusion receiving portion 35a does not have to be a through hole, and it is sufficient that it is formed longer than the protrusion length in the optical axis direction of the protrusion 37a.

[0051] Male thread portion 37b is a thread formed along the outer periphery of a part of the cylindrical or conical outer surface of holding member 37. When female thread portion 34a shown in FIG. 4 and male thread portion 37b are threadedly engaged with each other, holding member 37 is fitted into and fixed to lens barrel 34.

[0052] The elastic member 38 is made of a rubber material such as silicone rubber and is integrally formed in an annular (ring) shape. The elastic member 38 of Example 2 is positioned on the outer side of the protrusion 37a in the direction perpendicular to the optical axis, and is held by being disposed on the holding member 7 so that the inner surface of the elastic member 38 contacts the outer surface of the protrusion 37a.

[0053] Next, the procedure (steps) for holding the first optical element 35 and the other optical system 36 in the lens barrel 34 will be described. First, the elastic member 38 is inserted so that the inner surface of the elastic member 38 contacts the outer surface of the protrusion 37a of the holding member 37. Next, the other optical system 36 is inserted into the lens barrel 34. Next, the first optical element 35 is inserted. Next, the protrusion 37a of the holding member 37 holding the elastic member 38 is inserted into the protrusion receiving portion 35a of the first optical element 35. Next, the male thread portion 37b of the holding member 37 is screwed into the female thread portion 34a of the lens barrel 34, thereby fixing the holding member 37 and the lens barrel 34 in a state where the protrusion 37a and the protrusion receiving portion 35a are in contact (engage). As a result, the first optical element 35, the holding member 37, and the elastic member 38 rotate together when rotated in the rotational direction (circumferential direction) around the optical axis.

[0054] With the above configuration, the elastic member 38 can be held in a state where twisting or torsional deformation of the elastic member 38 is suppressed. As a result, it is possible to provide the optical device 1 in which the holding member 37 can hold (press) the first optical element 35 with a uniform force via the elastic member 38, as in the first embodiment.

[0055] 5, the protrusion receiving portion 35a is a round hole that is engaged with the protrusion 37a in the radial direction, but the protrusion receiving portion 35a may be an elongated hole extending in the radial direction. That is, the protrusion 37a and the protrusion receiving portion 35a may be engaged in the radial direction or the circumferential direction. Furthermore, the optical device 1 of the first and second embodiments is intended to be applied to an in-vehicle camera used for driving assistance or autonomous driving, but may be applied to devices other than an in-vehicle camera.

[0056] Example 3 Fig. 6 is a configuration diagram of an optical device 1 according to each of the above-described embodiments and an in-vehicle system (driving assistance device) 1000 including the same. The in-vehicle system 1000 is held by a movable body (mobile device) such as an automobile (vehicle), and is a control system for assisting the driving (steering) of the vehicle 500 based on distance information of objects such as obstacles and pedestrians around the vehicle acquired by the optical device 1. Fig. 7 is a schematic diagram of a vehicle 500 as a mobile device including the in-vehicle system 1000. Fig. 7 shows a case where the distance measurement range (detection range) of the optical device 1 is set in front of the vehicle 500, but the distance measurement range may also be set behind or to the side of the vehicle 500.

[0057] 6, the in-vehicle system 1000 includes an optical device 1, a vehicle information acquisition device 200, a control device (controller, ECU: Electronic Control Unit) 300, and a warning device (warning unit) 400. In the in-vehicle system 1000, a control unit (not shown) included in the optical device 1 has functions as a distance acquisition unit (acquisition unit) and a collision determination unit (determination unit). However, if necessary, the in-vehicle system 1000 may be provided with a distance acquisition unit and a collision determination unit separate from the control unit, or each may be provided outside the optical device 1 (for example, inside the vehicle 500). Alternatively, the control device 300 may be used as the control unit.

[0058] 8 is a flowchart showing an example of the operation of the in-vehicle system 1000 according to the embodiment 3. The operation of the in-vehicle system 1000 will be described below with reference to this flowchart.

[0059] First, in step S1, an object around the vehicle 500 is illuminated with illumination light from a light source forming unit (not shown) of the optical device 1, and the light reflected from the object is received. The control unit acquires distance information of the object based on a signal output by a light receiving element (light receiving unit) (not shown) upon receiving the reflected light. At this time, the distance acquisition unit functions as a distance information acquisition means that acquires distance information of the object based on the signal from the light receiving element. Here, the distance information may be information regarding the distance from the moving device (vehicle 500) to the object, and does not have to be the distance itself. Then, in step S2, the vehicle information acquisition device 200 acquires vehicle information of the vehicle 500, including the vehicle speed, yaw rate, steering angle, etc. Then, in step S3, the control unit uses the distance information acquired in step S1 and the vehicle information acquired in step S2 to determine whether the distance to the object is within a preset distance range.

[0060] This makes it possible to determine whether or not an object exists within a set distance around the vehicle 500, and to determine the possibility of a collision between the vehicle 500 and the object. Note that steps S1 and S2 may be performed in the reverse order to that described above, or may be performed in parallel with each other. If an object exists within the set distance, the control unit determines that there is a "possibility of collision" (step S4), and if there is no object within the set distance, the control unit determines that there is "no possibility of collision" (step S5).

[0061] Next, if the control unit determines that there is a "possibility of collision," it notifies (transmits) the determination result to the control device 300 and the warning device 400. At this time, the control device 300 controls the vehicle 500 based on the determination result of the control unit (step S6), and the warning device 400 issues a warning to the user (driver, passengers) of the vehicle 500 based on the determination result of the control unit (step S7). At this time, the warning device 400 functions as a warning means that issues a warning according to distance information of the object. Note that the notification of the determination result may be sent to at least one of the control device 300 and the warning device 400.

[0062] The control device 300 functions as a control means capable of controlling the driving and movement of the vehicle 500 by outputting control signals to the driving parts (engine, motor, etc.) of the vehicle 500. The control device 300 performs control such as applying the brakes on the vehicle 500, releasing the accelerator, turning the steering wheel, and generating control signals to generate braking forces on each wheel to suppress the output of the engine or motor. The warning device 400 warns the user by, for example, emitting a warning sound, displaying warning information on the screen of a car navigation system or the like, or vibrating the seat belt or steering wheel.

[0063] As described above, the in-vehicle system 1000 according to the third embodiment can detect and measure the distance to an object through the above-described processing, thereby making it possible to avoid a collision between the vehicle 500 and the object. In particular, by applying the optical device 1 according to each of the above-described embodiments to the in-vehicle system 1000, high distance measurement accuracy can be achieved, making it possible to detect an object and determine a collision with high accuracy.

[0064] In the third embodiment, the in-vehicle system 1000 is applied to driving assistance (collision damage reduction), but the application is not limited to this, and the in-vehicle system 1000 may be applied to cruise control (including an all-speed tracking function) or autonomous driving. The in-vehicle system 1000 is not limited to vehicles such as automobiles, but may be applied to moving bodies such as ships, aircraft, and industrial robots. The in-vehicle system 1000 is not limited to moving bodies, but may be applied to various devices that use object recognition, such as intelligent transport systems (ITS) and surveillance systems.

[0065] Furthermore, the in-vehicle system 1000 and the vehicle 500 may be provided with a notification device (notification unit) for notifying the manufacturer of the in-vehicle system or the dealer of the mobile device, etc., of the collision of the vehicle 500 with an obstacle. For example, the notification device may be one that transmits information (collision information) related to the collision between the vehicle 500 and the obstacle to a preset external notification destination by e-mail or the like.

[0066] In this way, by adopting a configuration in which the notification device automatically notifies collision information, it is possible to promptly take measures such as inspection and repair after a collision occurs. The destination of the collision information may be an insurance company, a medical institution, the police, or any other party set by the user. Furthermore, the notification device may be configured to notify the destination not only of collision information but also of malfunction information of each part and information on consumption of consumables. The detection of the presence or absence of a collision may be performed using distance information acquired based on the output from the above-mentioned light-receiving element, or may be performed by another detection unit (sensor).

[0067] Although the preferred embodiments of the present invention have been described above using examples, the present invention is not limited to these examples and various modifications and changes are possible within the scope of the present invention. In addition, the above-described examples may be combined and practiced.

[0068] Furthermore, a computer program that realizes part or all of the control in each of the above-described embodiments and the functions of each of the above-described embodiments may be supplied to the optical device 1, etc. via a network or various storage media. Then, a computer (or a CPU, MPU, etc.) in the optical device 1, etc. may read and execute the program. In this case, the program and the storage medium storing the program constitute the present invention. [Explanation of symbols]

[0069] 1 Optical device 2 Lens Module 3. Housing 4 Telescope tube 4a Male thread 4b Support part 5. First Optical Element 5a Protrusion receiving part 6 Other optical systems 7 Retaining member 7a Protrusion 7b Female thread 8 Elastic member

Claims

1. A lens holding mechanism for holding a lens, a lens barrel that houses the lens; a holding member that fits into the lens barrel and holds the lens in a direction along the optical axis; an elastic member disposed between the lens and the holding member; The holding member is formed with an engagement portion, A lens holding mechanism, characterized in that the lens is formed with an engaged portion that engages with the engaging portion in a radial or circumferential direction.

2. The engaging portion and the engaged portion have flat surfaces, 2. The lens holding mechanism according to claim 1, wherein the flat surface of the engaging portion and the flat surface of the engaged portion engage with each other in the radial direction or the circumferential direction.

3. 3. The lens holding mechanism according to claim 1, wherein the engagement portion has a protrusion that protrudes in a direction along the optical axis.

4. 4. The lens holding mechanism according to claim 1, wherein the elastic member is held by the holding member by being fitted into a recess formed in the holding member.

5. 5. The lens holding mechanism according to claim 1, wherein the elastic member is held radially outward of the engaging portion of the holding member.

6. The lens holding mechanism according to claim 1 , wherein the elastic member is held radially inward of the engaging portion of the holding member.

7. 7. The lens holding mechanism according to claim 1, wherein at least one of the lens and the holding member is made of a resin material.

8. a scanning unit that scans an object using illumination light from a light source; The lens holding mechanism according to any one of claims 1 to 7, An optical device, comprising: a scanning section that guides reflected light from the object illuminated by the scanning section to a light receiving element via the lens.

9. The optical device according to claim 8, a distance acquisition unit that acquires distance information of the object based on a signal from the light receiving element.

10. The control system according to claim 9 , further comprising a control device for controlling the driving of a mobile device that is a movable body based on the distance information.

11. 11. The control system according to claim 9, further comprising a warning device that issues a warning in response to the distance information of the object.

12. The optical device according to claim 8, a moving device comprising: a distance information acquiring means for acquiring distance information of the object based on a signal from the light receiving element;

13. 13. The moving device according to claim 12, further comprising a control unit that controls driving of the moving device based on the distance information.

14. 14. The mobile device according to claim 12, further comprising a warning unit that issues a warning in response to the distance information of the object.

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