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

Abstract

The present invention relates to a lens holding mechanism, an optical device, a control system, and a mobile device. A lens holding mechanism capable of pressing a peripheral portion of a lens in a direction along an optical axis while preventing distortion of an elastic member is provided. The lens holding mechanism includes a lens barrel configured to accommodate the lens, a pressing ring capable of moving in a direction along the optical axis with respect to the lens barrel, a rotating ring configured to rotate around the optical axis to move the pressing ring in the direction along the optical axis, and an elastic member provided between the lens and the pressing ring, wherein the lens barrel is provided with a rotation limiting portion configured to limit rotation of the pressing ring around the optical axis and a movement limiting portion configured to limit movement of the pressing ring in the direction along the optical axis, and wherein the elastic member is biased to the peripheral portion of the lens in the direction along the optical axis by moving the pressing ring in the direction along the optical axis.

Description

Technical Field

[0001] This invention relates to lens holding mechanisms, optical devices, control systems, and moving devices. Background Technology

[0002] Optical devices installed in vehicles, such as automobiles, include, for example, sensing devices for performing driver assistance and autonomous driving functions, and cameras for capturing images of the vehicle's surroundings. Optical devices with sensing capabilities include Light Detection and Ranging (LIDAR) devices, which are lidar devices that use lasers to measure distances between vehicles. In recent years, an increasing number of optical devices, such as LIDAR devices, have been installed in automobiles as onboard sensors for autonomous driving and other applications.

[0003] Optical devices used as vehicle sensors are typically exposed to harsh environmental changes. On the other hand, as a means to reduce the positional changes of each lens in response to environmental changes in the optical device (especially in response to changes in ambient temperature), a structure in which an elastic member is disposed between the lens and the pressure ring is known, for example, as described in Japanese Patent Application Publication No. S61-149911.

[0004] In the structure of Japanese Patent Application Publication No. S61-149911, as described above, an elastic member is disposed between the lens and the pressure ring. In the structure of Japanese Patent Application Publication No. S61-149911, the elastic member may twist due to the contact resistance between the pressure ring and the elastic member. If the elastic member twists, problems arise such as uneven biasing force applied to the lens and the elastic member protruding into the effective beam area.

[0005] Furthermore, as described in Japanese Patent Application Publication No. S61-149911, even if friction damping plates are inserted in front of and behind the elastic member, the elastic member will still twist due to the tightening force of the pressure ring, making it difficult to control the amount of twisting of the elastic member.

[0006] Devices such as the aforementioned optical apparatus have a lens barrel that holds the optical elements. When the optical elements are held in the lens barrel, if the ambient temperature changes, the difference in the amount of expansion and contraction between the optical elements and the lens barrel due to the difference in their coefficients of linear expansion may cause a gap (loosening) in the optical axis direction. This loosening may alter the holding position, potentially leading to reduced optical performance and component degradation over time. In temperature environments with wide temperature variations, automotive cameras, LiDAR devices, and similar applications are required to ensure excellent performance and functionality across the entire temperature range.

[0007] Furthermore, due to cost considerations, automotive cameras typically do not include an autofocus mechanism. On the other hand, there exists a construction in which a ring-shaped elastic member is clamped and held between a pressure ring and an optical element, and this ring-shaped elastic member is pre-compressed to the required amount during assembly at room temperature to provide elastic force and eliminate loosening at high temperatures. It is believed that the requirements for driver assistance and autonomous driving functions in automobiles will be higher in performance and functionality than currently available, and that the optical systems of automotive cameras, which act as the eyes of the car, will need to become more complex and highly functional.

[0008] It is also believed that as the optical systems of vehicle cameras become more complex and highly functional, as described above, the number of optical elements will increase, and the loosening of the retaining ring, lens barrel, optical elements, etc., due to temperature changes may become more significant. Furthermore, for example, when the optical device is externally attached to a car, the elastic member can be used for drip-proof and waterproof purposes in rainy weather. Japanese Patent No. 6192560 discloses a structure in which the retaining ring and the elastic member together hold the optical element in a state that allows contact with the optical element. Japanese Patent Application Publication No. H05-127058 discloses a structure in which the optical element is held by the retaining ring via the elastic member.

[0009] In Japanese Patent No. 6192560 and Japanese Patent Application Publication No. H05-127058, the retaining ring is rotated and screwed in during assembly. In this configuration, due to friction between the elastic member and both the retaining ring and the optical element, there is a risk that the elastic member may undergo deformation (e.g., torsion or twisting). If the optical element is held in a deformed state, the retaining ring will not be able to apply a uniform force to hold the optical element within the lens barrel. Therefore, there is a risk of reduced assembly accuracy, i.e., reduced optical performance, due to factors such as tilting of the optical element.

[0010] Furthermore, if the ambient 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 materials, the deformation of the elastic member and the amount released from the compressed state will differ to some extent, taking into account the loosening that has already occurred. Therefore, optical performance may further deteriorate when the ambient temperature changes. Summary of the Invention

[0011] The purpose of this invention is to provide a lens holding mechanism that can press the peripheral portion of a lens along the optical axis while preventing the elastic member from twisting.

[0012] According to one aspect of the invention, a lens holding mechanism is a lens holding mechanism for holding a lens, the lens holding mechanism comprising a lens barrel configured to receive the lens, a retaining ring configured to move relative to the lens barrel in a direction along an optical axis, a rotating ring configured to rotate about the optical axis to move the retaining ring in the direction along the optical axis, and an elastic member disposed between the lens and the retaining ring, wherein the lens barrel is provided with a rotation limiting portion and a movement limiting portion, the rotation limiting portion being configured to limit the rotation of the retaining ring about the optical axis, the movement limiting portion being configured to limit the movement of the retaining ring in the direction along the optical axis, and wherein, by moving the retaining ring in the direction along the optical axis, the elastic member is biased against a peripheral portion of the lens in the direction along the optical axis.

[0013] Other features of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0014] Figure 1 This is a view showing an example of the structure of an optical device according to the first embodiment.

[0015] Figure 2 This is a cross-sectional view showing the structure of the telescope according to the first embodiment.

[0016] Figure 3 This is a cross-sectional view of the optical device in the lens unit according to the second embodiment and its surroundings.

[0017] Figure 4 This is a schematic cross-sectional view of the optical device according to the third embodiment.

[0018] Figure 5 It shows Figure 4 Examples of exploded perspective views of optical elements, elastic components, and retaining components.

[0019] Figure 6 It shows a change Figure 4 A cross-sectional view of an example of an optical element and a retaining member.

[0020] Figure 7 This is a cross-sectional view showing an example of a lens module according to the fourth embodiment.

[0021] Figure 8 This is an exploded perspective view showing an example of an optical element, an elastic member, and a retaining member according to a fourth embodiment.

[0022] Figure 9 This is a structural diagram of the vehicle-mounted system according to the fifth embodiment.

[0023] Figure 10This is a schematic diagram of a vehicle that includes a vehicle-mounted system according to the fifth embodiment.

[0024] Figure 11 This is a flowchart illustrating exemplary operation of an in-vehicle system according to a fifth embodiment. Detailed Implementation

[0025] Hereinafter, preferred embodiments will be described with reference to the accompanying drawings. Repeated descriptions when referring to the various drawings will be omitted or simplified.

[0026] First Embodiment

[0027] Figure 1 This is a view showing the structure of the optical device (optical instrument) 100 according to the first embodiment. (See diagram below.) Figure 1 As shown, the optical device 100 of the first embodiment is a so-called coaxial LIDAR device, wherein the optical axis of the illumination system illuminating the object is aligned with the optical axis of the receiving system receiving reflected and scattered light from the object at the perforated lens 4.

[0028] The optical device 100 according to the first embodiment includes a perforated mirror 4, a fixed mirror 5, a movable mirror 6, a condenser lens 7, a light receiving element 8, a base lens barrel 9, a light source forming part (light projection part) 10, a control unit 14, and a telescope 20.

[0029] The perforated mirror (light guide) 4 is a reflector fixedly held by the base mirror barrel 9 and has a hole 4a (opening). The perforated mirror 4 allows laser 12 to be transmitted through the hole 4a and reflected by the reflective surface 4b. The perforated mirror 4 guides the laser 12 from the light source forming part 10 to the fixed mirror 5 and guides the reflected light from the fixed mirror 5 to the condenser lens 7. The fixed mirror 5 is a reflector fixedly held by the base mirror barrel 9. The fixed mirror 5 guides the laser 12 from the perforated mirror 4 to the movable mirror 6 and guides the reflected light from the movable mirror 6 to the perforated mirror 4.

[0030] The movable mirror (deflection section or scanning section) 6 is a reflector that is fixedly held by the base mirror tube 9 and scans the object using illumination light from the light source forming section 10. The movable mirror 6 is configured to surround... Figure 1 The movable mirror 6 is a dual-axis driven mirror that rotates along the Y-axis and the X-axis perpendicular to the Y-axis. An example of the movable mirror 6 includes a microelectromechanical system (MEMS) reflector. The movable mirror 6 uses a laser 12 from the fixed mirror 5 to illuminate the target area via the lens (optical element) of the telescope 20, and guides the reflected light 13 from the obstacle 11 in the target area to the fixed mirror 5 via the lens of the telescope 20.

[0031] The condenser lens 7 is an optical element (condenser optical element) that is fixedly held by the base lens barrel 9, focuses the laser 12 from the perforated mirror 4, and guides the focused laser 12 to the light receiving element 8. The light receiving element 8 is a component used to perform photoelectric conversion on the illumination light from the light source forming section 10 and output a signal. A photodiode (PD), avalanche photodiode (APD), or single-photon avalanche diode (SPAD) is used as the light receiving element 8. The perforated mirror 4, fixed mirror 5, movable mirror 6, condenser lens 7, and light receiving element 8 are included and housed in the base lens barrel 9.

[0032] The light source forming unit (light projection unit) 10 includes a light source (semiconductor laser) 1, a converging lens 2, and a fixed aperture 3. The light source 1 is a light source that emits laser light (irradiation light) 12. The converging lens 2 is an optical element that adjusts the beam shape of the laser light 12 from the light source 1 in the target irradiation area. The fixed aperture 3 is configured to block unwanted light included in the laser light 12 emitted from the light source 1 via the converging lens 2, and projects light through its opening 3a.

[0033] The control unit 14 comprises at least one computer, including a CPU, a memory (storage unit), etc. The control unit 14 is connected via wiring to each component of the optical device 100. The control unit 14 controls the overall operation and adjustment of all components of the optical device 100 according to a computer program stored in the memory. This control will be described later. Figure 11 The flowchart shown illustrates the operation. For example, the control unit 14 is preferably integrated with other parts of the optical device 100, but it can also be configured separately from other parts of the optical device 100.

[0034] In the first embodiment, the control unit 14 controls the light source 1, the movable mirror 6, the light receiving element 8, etc. Specifically, the control unit 14 drives the light source 1 and the movable mirror 6 with a predetermined driving voltage and driving frequency, and measures the waveform of the light received by the light receiving element 8 at a specific frequency. Then, the control unit 14 measures the difference between the time when the light receiving element 8 receives light and the time when light is emitted from the light source 1, or measures the difference between the phase of the light received signal acquired by the light receiving element 8 and the phase of the output signal from the light source 1, and multiplies this difference by the speed of light to determine the distance to the object.

[0035] The telescope (lens holding mechanism) 20 is an optical system that expands the beam diameter of the laser 12 from the movable mirror 6 and reduces the beam diameter of the reflected light 13 from the obstacle 11 (object). Specifically, the telescope 20 is an optical system (afocal system) comprising multiple optical elements (lenses), each of which has refractive power, but the system as a whole does not have refractive power. The construction of the telescope 20 will be described later.

[0036] Here, the laser 12 emitted from the light source forming section 10 of the optical device 100 according to the first embodiment is projected into the base lens barrel 9 through the opening 3a of the fixed aperture 3. The laser 12 projected through the opening 3a of the fixed aperture 3 passes through the hole 4a of the perforated mirror 4, is reflected by the fixed mirror 5, and is irradiated onto the target area by the movable mirror 6.

[0037] Laser 12 emitted from telescope 20 to the target area is reflected by obstacle 11 in the target area, passing through telescope 20 as reflected light 13 and returning to movable mirror 6. The reflected light 13, reflected by movable mirror 6, is then reflected by fixed mirror 5. Subsequently, the reflected light 13 is reflected by the reflecting surface 4b of perforated mirror 4 and guided to condenser lens 7. The reflected light 13 emitted from condenser lens 7 is guided to light receiving element 8. Light receiving element 8 performs photoelectric conversion on the reflected light 13 and outputs a signal.

[0038] Figure 2 This is an example of a cross-sectional view showing the construction of the telescope 20 according to the first embodiment. Reference will be made below. Figure 2 The structure of the telescope 20 is described. The telescope 20 of the first embodiment includes a lens 21, a lens 22, a spacer 23, a fixed lens tube 24, a pressure ring 25, a rotating ring 26, and an elastic member 27.

[0039] The outer diameters of lens 21 and spacer 23 are formed to be smaller than the inner diameter 24a of fixed lens barrel 24. Specifically, the outer diameters of lens 21 and spacer 23 are formed to be approximately 10 to 20 μm smaller than the inner diameter 24a of fixed lens barrel 24. The outer diameter of lens 22 is also formed to be smaller than the inner diameter 24b of fixed lens barrel 24. Specifically, the outer diameter of lens 22 is formed to be approximately 10 to 20 μm smaller than the inner diameter 24b of fixed lens barrel 24. Therefore, lens 21, lens 22, and spacer 23 can be accommodated in fixed lens barrel 24 such that they are arranged along the optical axis.

[0040] The spacer 23 has corner portions 23a and 23b that are in line contact with the R2 surface of lens 21 and the R1 surface of lens 22, respectively, and controls the eccentricity of lenses 21 and 22 in a direction orthogonal to the optical axis (radial direction) and the spacing between them in the optical axis direction.

[0041] The position of the retaining ring 25 relative to the fixed lens barrel 24 in the optical axis direction is determined by abutting the annular end face 25d provided on the inner diameter of the retaining ring 25 against the protrusion (movement restriction part) 24d provided in annular shape on the fixed lens barrel 24. The protrusion 24d is formed to protrude radially outward by a predetermined amount in a direction orthogonal to the optical axis. The position of the retaining ring 25 in the direction orthogonal to the optical axis is determined by assembling the inner diameter mounting part 25e of the retaining ring 25 and the outer diameter mounting part 24e of the fixed lens barrel 24 together.

[0042] The elastic member 27 is made of a component made of rubber or the like and is integrally formed into a ring shape. When in contact with the peripheral portion of the lens 21, since the elastic member 27 is integrally formed into a ring shape, the elastic member 27 contacts the entire circumference of the lens 21. The elastic member 27 preferably has an integrally formed ring shape as described above, but it may also have a ring shape that contacts, for example, a portion of the lens 21. The elastic member 27 may also be composed of, for example, three separate elastic members that contact the lens 21 at predetermined intervals (e.g., 120-degree intervals).

[0043] An elastic member 27 is disposed between the lens 21 and the retaining ring 25. Specifically, the elastic member 27 is held by the retaining ring 25 by arranging it to fit into a groove 25a formed in an annular shape on the retaining ring 25. The groove 25a clamps and guides the elastic member 27, for example, so that the mounting position of the elastic member 27 does not shift (move) or the elastic member 27 does not disengage when assembling the optical device 100 or the telescope 20. The groove 25a can be, for example, a recess (including concave and equivalent shapes) or a semicircle, and can be of any shape as long as the position of the elastic member 27 does not shift when it is disposed in the groove 25a. The groove 25a can be disposed on the lens 21 on the R1 surface side, in which case the groove may not be provided on the retaining ring 25.

[0044] Next, the keyway 25b on the inner diameter of the retaining ring 25 is assembled with the key (rotation limiting part) 24c of the fixed lens barrel 24. This restricts the rotation of the retaining ring 25 around the optical axis (circumferential direction). Further, at this time, the external thread portion 25c on the outer diameter of the retaining ring 25 (on the outer circumferential side in the direction orthogonal to the optical axis) is screwed into the internal thread portion 26a on the inner diameter of the rotating ring 26 (on the inner circumferential side in the direction orthogonal to the optical axis). Thus, the retaining ring 25 and the rotating ring 26 are assembled together and fixed. Rotating the rotating ring 26 around the optical axis in this state allows the retaining ring 25 to move only in the direction of the optical axis.

[0045] In manufacturing the structure of the first embodiment, when the retaining ring 25 and the fixed lens barrel 24 are assembled together, and then the retaining ring 25 and the rotating ring 26 are assembled together, a predetermined gap is formed between the protrusion 24d of the fixed lens barrel 24 and the end face 25d of the retaining ring 25. This predetermined gap is formed to have a predetermined width dimension (space B) in the optical axis direction. The width dimension of space B is such that the elastic member 27 contacts the R1 surface of the lens 21 and the elastic member 27 is not biased onto the lens 21. The width dimension in the optical axis direction of space B is formed such that the gap satisfies the following formula (1) relative to the cross-sectional dimension ΦA of the elastic member 27.

[0046] ΦA > B ... (1)

[0047] As shown in formula (1) above, the width dimension of the interval B is smaller than the cross-sectional dimension ΦA of the elastic member 27. Therefore, the amount of deformation of the elastic member 27 in the optical axis direction is determined by the interval B, which is the width dimension in the optical axis direction.

[0048] As the rotating ring 26 rotates around the optical axis, the pressure ring 25 moves along the optical axis and biases the R1 surface of the lens 21 along the optical axis using the elastic member 27 between the pressure ring 25 and the lens 21. Due to the biasing force of the elastic member 27, the annular stop 26b provided on the inner diameter of the rotating ring 26 contacts the protrusion 24d of the fixed lens barrel 24 in the optical axis direction. When the end face 25d of the pressure ring 25 moves further until it abuts against the protrusion 24d of the fixed lens barrel 24, the elastic member 27 deforms at interval B, thus biasing the lens 21, lens 22 and spacer 23 onto the receiving surface 24f of the fixed lens barrel 24.

[0049] Because the interval B is smaller than the cross-sectional dimension ΦA of the elastic member 27, even when the rotating ring 26 rotates around the optical axis and the end face 25d of the pressure ring 25 abuts against the protrusion 24d, the deformation of the elastic member 27 in the optical axis direction can be made approximately uniform. The pressure ring 25 is movable only in the optical axis direction. Therefore, when the pressure ring 25 moves along the optical axis direction and the elastic member 27 is biased against the lens 21, the elastic member 27 will not twist due to torque and will contact the peripheral portion of the lens 21 throughout the circumference, allowing it to press the lens 21 evenly.

[0050] In the first embodiment, for example, the coefficient of linear expansion is 26 × 10⁻⁶. -6 Aluminum alloy of / ℃ can be used to fix the lens barrel 24, the retaining ring 25, the rotating ring 26, and the spacer 23. Lenses 21 and 22 use a linear expansion coefficient of 7×10. -6 Glass material at / ℃.

[0051] Here, as an example, assume that the thickness of the aluminum alloy spacer 23 is 5 mm, and the distance between the receiving portion on the R1 surface of the glass lens 21 and the receiving portion on the R2 surface of the lens 22 is 15 mm. The receiving portion on the R1 surface of the lens 21 is the part of the lens 21 that contacts the elastic member 27, and the receiving portion on the R2 surface of the lens 22 is the part of the lens 22 that contacts the receiving surface 24f of the fixed lens barrel 24.

[0052] At this time, when the temperature changes by 1°C, a thermal expansion difference of approximately 0.19 μm occurs between the receiving portion on the R1 surface of lens 21 and the receiving portion on the R2 surface of lens 22. That is, when the temperature changes by 1°C, a gap difference of approximately 0.19 μm occurs between the fixed lens barrel 24 and the lens. For example, when the optical device 100 is placed in an external environment (e.g., outdoors), in an environment where the ambient temperature and the internal temperature of the optical device 100 are 60°C higher than the temperature at which the optical device 100 was assembled, approximately 11.4 μm of loosening (loosening amount) will occur in the optical axis direction. On the other hand, in an environment where the ambient temperature is 60°C lower than the temperature at which the optical device 100 was assembled as described above, approximately 11.4 μm of lens deformation will occur in the optical axis direction.

[0053] Assuming the optical device 100 according to the first embodiment is used in autonomous driving or similar applications, and is applied to a LIDAR device that uses lasers to measure distances between vehicles, the optical device 100 is frequently exposed to harsh environmental changes. Therefore, if, as described above, loosening occurs in the optical axis direction due to large temperature variations, there is a possibility, for example, that lenses 21 and 22 may shift in a direction orthogonal to the optical axis (i.e., become off-center). Alternatively, there is a possibility that lenses 21 and 22 may deform and aberrations may become more severe. It is conceivable that these would cause shifts in the projection and imaging positions, reducing the measurement accuracy of the obstacle 11. It is also conceivable that, for example, measurements of minute feature points on the surface of the obstacle 11 would become difficult.

[0054] In the first embodiment, the elastic member 27, which is disposed in the groove 25a of the pressure ring 25, contacts the lens 21, and biases the lens along the optical axis, elastically deforms to absorb the looseness in the optical axis direction as described above. That is, in an environment where the ambient temperature is 60°C higher or lower than the temperature when assembling the optical device 100, the length of the lens changes by approximately 11.4 μm in the optical axis direction, but the deformation of the lens can be absorbed by the elastic member 27. For looseness occurring in the direction orthogonal to the optical axes of lenses 21 and 22 (in the radial direction), when the device is exposed to the above environment, the protrusion 24d of the fixed lens barrel 24 abuts against the end face 25d of the pressure ring 25. Therefore, lenses 21 and 22 are pressed by the spacer 23 and the elastic member 27, thereby reducing relative eccentricity.

[0055] In the optical device 100 according to the first embodiment, as described above, the elastic member 27 can absorb the loosening of lenses 21 and 22, etc., included in the telescope 20 in the optical axis direction. That is, when a single elastic member 27, formed in a ring shape, presses against multiple lenses (lenses 21 and 22) and spacers 23, the elastic member 27 can absorb the amount of loosening of the multiple lenses and spacers caused by the difference in linear expansion due to temperature changes. Furthermore, since the pressure ring 25 is movable only in the optical axis direction, the pressure ring 25 can press against the peripheral portion of the lens uniformly without causing the elastic member 27 to twist due to torque. In addition, since the size of the spacer B is smaller than the cross-sectional size ΦA of the elastic member 27, the elastic member 27 deforms at most only the size of the predetermined gap spacer B. Therefore, the deformation of the elastic member 27 in the optical axis direction can be made substantially uniform, and the peripheral portion of the lens 21 can be pressed uniformly.

[0056] A first embodiment has been described with respect to a structure consisting of two lenses for the telescope 20; however, the number of lenses is not limited to two, and may include one or more. In the first embodiment, it is also assumed that the invention is applied to a telescope of a LIDAR device as a laser illumination device (laser radar device); however, the invention is not limited thereto and may also be applied to other devices besides laser illumination devices.

[0057] Second Embodiment

[0058] The first embodiment has been described with reference to an example in which the elastic member 27 is used as part of the front lens (lens 21) of the telescope for fixing the LIDAR device. The second embodiment will be described with reference to a mode in which the lens is held by a sensor holder 35 that holds the image pickup element 30 in the imaging lens unit. Matters not mentioned in the second embodiment are consistent with those in the first embodiment.

[0059] Figure 3 This is a view showing the structure of the optical device 100 according to the second embodiment. Specifically, Figure 3 This is a cross-sectional view of the image pickup element 30 and its surroundings in the imaging lens unit (lens holding mechanism) of the optical device 100.

[0060] exist Figure 3In this structure, lens 31, lens 32, and spacer 33 are contained within a fixed lens barrel 34 and constitute part of an imaging lens unit. The outer diameter of lens 31 is formed to be smaller than the inner diameter 34a of the fixed lens barrel 34. Specifically, the outer diameter of lens 31 is formed to be approximately 10 to 20 μm smaller than the inner diameter 34a of the fixed lens barrel 34. The outer diameters of lens 32 and spacer 33 are also formed to be smaller than the inner diameter 34b of the fixed lens barrel 34. Specifically, the outer diameters of lens 32 and spacer 33 are formed to be approximately 10 to 20 μm smaller than the inner diameter 34b of the fixed lens barrel 34. Therefore, lens 31, lens 32, and spacer 33 can be accommodated within the fixed lens barrel 34 such that they are arranged along the optical axis.

[0061] The spacer 33 has corner portions 33a and 33b that are in line contact with the R2 surface of lens 31 and the R1 surface of lens 32, respectively, and controls the eccentricity of lenses 31 and 32 in a direction orthogonal to the optical axis and the spacing between them in the optical axis direction.

[0062] The image acquisition element 30 is fixedly held by the sensor holder 35, and the position of the sensor holder 35 relative to the fixed lens barrel 34 in the optical axis direction is determined by abutting an annular end face 35d provided on the sensor holder 35 against an annular protrusion (movement restriction portion) 34d provided on the inner diameter of the fixed lens barrel 34. The protrusion 34d is formed to protrude radially outward by a predetermined amount in a direction orthogonal to the optical axis. The position of the sensor holder 35 in the direction orthogonal to the optical axis is determined by assembling the inner diameter mounting portion 35e of the sensor holder 35 and the outer diameter mounting portion 34e of the fixed lens barrel 34 together.

[0063] An elastic member 37 is disposed between the lens 32 and the sensor holder 35. Specifically, the elastic member 37 is held by the sensor holder 35 by arranging it to fit into a groove 35a formed in an annular shape on the sensor holder 35. The groove 35a clamps and guides the elastic member 37, for example, so that the mounting position of the elastic member 37 does not shift (move) or the elastic member 27 does not disengage during the assembly of the optical device 100 or the imaging lens unit.

[0064] Furthermore, the keyway 35b on the inner diameter of the sensor holder 35 is fitted with the key (rotation limiting part) 34c of the fixed lens barrel 34. This restricts the rotation of the sensor holder 35 around the optical axis. Further, the external thread portion 35c on the outer diameter of the sensor holder 35 is screwed into the internal thread portion 36a on the inner diameter of the rotating ring 36. Therefore, the sensor holder 35 and the rotating ring 36 are assembled together and fixed. Rotating the rotating ring 36 around the optical axis in this state allows the sensor holder 35 to move only in the direction of the optical axis.

[0065] When manufacturing the optical device 100 of the second embodiment, when the sensor holder 35 and the fixed lens barrel 34 are assembled together, and then the sensor holder 35 and the rotating ring 36 are assembled together, a predetermined gap is formed between the protrusion 34d of the fixed lens barrel 34 and the end face 35d of the sensor holder 35. This predetermined gap is formed to have a predetermined width dimension (space D) in the optical axis direction. The width dimension of space D is such that the elastic member 37 contacts the R2 surface of the lens 32 and the elastic member 37 is not biased on the lens 32. The width dimension in the optical axis direction of the gap space D is formed such that it satisfies the following formula (2) relative to the cross-sectional dimension ΦC of the elastic member 37.

[0066] ΦC>D...(2)

[0067] As shown in formula (2) above, the width dimension of the interval D is smaller than the cross-sectional dimension ΦC of the elastic member 37. Therefore, the amount of deformation of the elastic member 37 in the optical axis direction is determined by the interval D, which is the width dimension in the optical axis direction.

[0068] As the rotating ring 36 rotates around the optical axis, the sensor holder 35 moves along the optical axis and biases the R2 surface of the lens 32 along the optical axis using the elastic member 37 between the sensor holder 35 and the lens 32. Due to the biasing force of the elastic member 37, the annular stop 36b provided on the inner diameter of the rotating ring 36 contacts the protrusion 34d provided on the fixed lens barrel 34 in the optical axis direction. When the end face 35d of the sensor holder 35 moves further until it abuts against the protrusion 34d of the fixed lens barrel 34, the elastic member 37 deforms at interval D, thus biasing the lens 32, lens 31 and spacer 33 onto the receiving surface 35f of the sensor holder 35.

[0069] Because the interval D is smaller than the cross-sectional dimension ΦC of the elastic member 37, even if the rotating ring 36 rotates around the optical axis and the end face 35d of the sensor holder 35 abuts against the protrusion 34d, the deformation of the elastic member 37 in the optical axis direction can be made approximately uniform. The sensor holder 35 is movable only in the optical axis direction. Therefore, when the sensor holder 35 moves along the optical axis direction and the elastic member 37 is biased against the lens 32, the elastic member 37 will not twist due to torque and will contact the peripheral portion of the lens 32 around the entire circumference, allowing it to press the lens 32 evenly.

[0070] In the second embodiment, for example, the coefficient of linear expansion is 26 × 10⁻⁶. -6 Aluminum alloy of / ℃ can be used to fix the lens barrel 34, sensor holder 35, rotating ring 36, and spacer 33. Lenses 31 and 32 use a linear expansion coefficient of 7×10. -6 Glass material at / ℃.

[0071] Here, as an example, assume that the thickness of the aluminum alloy spacer 33 is 5 mm, and the distance between the receiving portion on the R1 surface of the glass lens 31 and the receiving portion on the R2 surface of the lens 32 is 15 mm. The receiving portion on the R1 surface of the lens 31 is the portion of the lens 31 that contacts the receiving surface 35f of the sensor holder 35, and the receiving portion on the R2 surface of the lens 32 is the portion of the lens 32 that contacts the elastic member 37.

[0072] At this time, when the temperature changes by 1°C, a thermal expansion difference of approximately 0.19 μm occurs between the receiving portion on the R1 surface of lens 31 and the receiving portion on the R2 surface of lens 32. That is, a gap difference of approximately 0.19 μm occurs between the fixed lens barrel 34 and the lens. For example, when the optical device 100 is placed in an external environment (e.g., outdoors), for example, in an environment where the ambient temperature and the internal temperature of the optical device 100 are 60°C higher than the temperature at which the optical device 100 was assembled, approximately 11.4 μm of loosening (loosening amount) occurs in the optical axis direction. On the other hand, in an environment where the ambient temperature is 60°C lower than the temperature at which it was assembled as described above, approximately 11.4 μm of lens deformation occurs in the optical axis direction. Similar to the first embodiment, assuming that the optical device 100 according to the second embodiment is used for autonomous driving, etc., and applied to a LIDAR device, which is a laser illumination device that uses lasers to measure the distance between vehicles.

[0073] In the second embodiment, the elastic member 37, which is disposed in the groove 35a of the sensor holder 35, contacts the lens 32, and biases the lens along the optical axis, elastically deforms to absorb the looseness in the optical axis direction as described above. That is, in an environment where the ambient temperature is 60°C higher or lower than the temperature when assembling the optical device 100, the length of the lens changes by approximately 11.4 μm in the optical axis direction, but the deformation of the lens can be absorbed by the elastic member 27. For looseness occurring in the direction orthogonal to the optical axes of lenses 31 and 32 (in the radial direction), when the device is exposed to the above environment, the protrusion 34d of the fixed lens barrel 34 abuts against the end face 35d of the sensor holder. Therefore, lenses 31 and 32 are pressed by the spacer 33 and the elastic member 37, thereby reducing relative eccentricity.

[0074] In the optical device 100 according to the second embodiment, as described above, the elastic member 37 can absorb the loosening of lenses 31 and 32, etc., included in the imaging lens unit in the optical axis direction. That is, when a single elastic member 37, formed in an annular shape, presses against multiple lenses (lenses 31 and 32) and spacers 33, the elastic member 37 can absorb the amount of loosening of the multiple lenses and spacers caused by the difference in linear expansion due to temperature changes. Furthermore, similar to the first embodiment, since the sensor holder 35 is movable only in the optical axis direction, the sensor holder 35 can press against the peripheral portion of the lens uniformly without causing the elastic member 37 to twist due to torque. In addition, since the size of the gap D is smaller than the cross-sectional size ΦC of the elastic member 37, the elastic member 37 deforms at most only the size of the predetermined gap D. Therefore, the deformation of the elastic member 37 in the optical axis direction can be made substantially uniform, and the peripheral portion of the lens can be pressed uniformly.

[0075] The second embodiment has been described with respect to the structure of the imaging lens unit consisting of two lenses, but the number of lenses is not limited to two, and can be any number of more than one.

[0076] Third Embodiment

[0077] Figure 4 This is a schematic cross-sectional view of the optical device 100 according to the third embodiment. Figure 5 This is an example of an exploded perspective view of the first optical element 5, the retaining member 7, and the elastic member 8 according to the third embodiment. Reference will be made below. Figure 4 and Figure 5 The optical device 100 of the third embodiment is described.

[0078] The optical device 100 of the third embodiment includes a lens module 2, a housing 3, an electrical device (not shown), and a control unit (not shown). Although not shown, the optical device 100 also includes a perforated lens, a fixed lens, a movable lens, a condenser lens, a light receiving element, a light source forming section (light projection section), etc. Here, for example, when the optical device 100 is a vehicle-mounted camera, the lens module 2 serves as an imaging optical system, and when a signal is input to the electrical device (not shown) including an image sensor, it acquires environmental information about the vehicle's surroundings. The acquired information is used, for example, in a driver assistance or autonomous driving system.

[0079] Lens module 2 includes lens barrel 4, first optical element 5, another optical element 6, retaining member 7, and elastic member 8. The retaining member 7 holds the first optical element 5 and the other optical element 6, which are arranged with spacers (not shown), in the lens barrel 4. Lens module 2 is held by housing 3.

[0080] The housing 3 houses a perforated mirror, a fixed mirror, a movable mirror, a condenser lens, a light receiving element, a light source forming section (light projection section), etc. (not shown). The perforated mirror (light guide section) is a reflector fixedly held by the housing 3 and has an opening. The perforated mirror allows illumination light (e.g., laser light) to pass through the opening and be reflected by a reflective surface. The perforated mirror guides the laser light from the light source forming section to the fixed mirror and guides the reflected light from the fixed mirror to the condenser lens. The fixed mirror is a reflector fixedly held by the housing 3. The fixed mirror guides the illumination light from the perforated mirror to the movable mirror and guides the reflected light from the movable mirror to the perforated mirror.

[0081] The movable mirror (deflection section or scanning section) is a reflective mirror that is fixedly held by the housing 3 and scans the object using illumination light from the light source forming section. The movable mirror can be configured as a dual-axis driven mirror, and, for example, a MEMS mirror can be used as the movable mirror. The movable mirror uses illumination light from the fixed mirror to illuminate the target area via optical elements (first optical element 5 and another optical element 6), and guides the reflected light from the object in the target area to the fixed mirror via the optical elements.

[0082] The condenser lens is an optical element (condenser optical element) that is fixedly held by the housing 3, converges the illumination light from the perforated mirror, and guides the converged illumination light to the light receiving element. The light receiving element is a component used to perform photoelectric conversion on the illumination light from the light source forming part and output a signal. PD, APD, SPAD, etc., are used as light receiving elements. The perforated mirror, fixed mirror, movable mirror, condenser lens, light receiving element, etc., are included and housed in the housing 3.

[0083] The light source forming section (light projection section) includes a light source unit (semiconductor laser), a converging lens, and a fixed aperture. The light source unit is the light source that emits illumination light. The converging lens is an optical element that adjusts the shape (beam shape) of the illumination light from the light source unit in the target illumination area. The fixed aperture is configured to block unwanted light included in the illumination light emitted from the light source unit via the converging lens, and projects light through its opening.

[0084] The lens barrel 4 has an external threaded portion 4a and a support portion 4b, and houses a first optical element 5 and another optical element 6. In the third embodiment, the lens barrel 4 is made of metal or resin. The external threaded portion 4a is a threaded portion formed along the outer periphery of the lens barrel 4 on a portion of its cylindrical or conical outer surface. The support portion 4b is a surface perpendicular to the optical axis (orthogonal to the optical axis), facing a side surface of the other optical element 6 in the direction of the optical axis, and this support portion supports the first optical element 5 and the other optical element 6. Here, the support portion 4b is not limited to a surface perpendicular to the optical axis; it can also be a surface inclined relative to the optical axis.

[0085] The first optical element (lens) 5 has a protruding receiving portion (joined portion) 5a. In the third embodiment, the protruding receiving portion 5a is configured to have a planar surface (planar portion) on the outer diameter portion of the first optical element 5 (on the outer periphery in the direction orthogonal to the optical axis). Here, in the third embodiment, one protruding receiving portion 5a is provided on the first optical element 5. However, if multiple protrusions 7a, which will be described later, are formed, multiple protruding receiving portions 5a can be formed according to the number of protrusions 7a formed. The first optical element 5 is configured as a convex lens. However, the first optical element 5 is not limited to this and can also be configured in the shape of a concave lens or an aspherical lens. The first optical element 5 is made of a transparent component such as glass or resin.

[0086] The retaining member 7 has a protrusion (engaging portion) 7a and an internally threaded portion 7b. The protrusion 7a is formed to protrude a predetermined length in the optical axis direction and is configured to have a planar surface (planar portion) at the position where it abuts (engages) the planar portion of the protrusion receiving portion 5a when the lens module 2 is assembled. The length of the protrusion 7a in the optical axis direction is set such that when the lens module 2 is assembled, it does not protrude beyond the end of the first optical element 5 on the side of the other optical element 6. Therefore, the protruding length of the protrusion 7a in the optical axis direction can be arbitrarily set, as long as it does not protrude beyond the end of the first optical element 5 on the side of the other optical element 6 and abuts the protrusion receiving portion 5a at an appropriate length.

[0087] Although the third embodiment retains one protrusion 7a on the member 7, the invention is not limited thereto, and multiple protrusions 7a may also be formed. In this case, a protrusion receiving portion 5a is formed on the first optical element 5 according to the number and position of the protrusions 7a. Figure 4 and Figure 5 The protruding receiving portion 5a abuts (engages) the protrusion 7a in the radial direction, but a small radial gap may exist between the protruding receiving portion 5a and the protrusion 7a. That is, the protrusion 7a and the protruding receiving portion 5a only need to engage with each other in the radial or circumferential direction.

[0088] The internal thread portion 7b is a threaded portion formed along the inner circumference of the retaining member 7 on a portion of the cylindrical or conical inner surface of the retaining member 7. By... Figure 4 The external threaded portion 4a and the internal threaded portion 7b shown are screwed together to hold the component 7 assembled and fixed to the lens barrel 4.

[0089] The retaining member 7 has an annular groove in which the elastic member 8 will be disposed. The groove is formed on the retaining member 7 such that it is located radially inward of the surface of the protrusion 7a in a direction orthogonal to the optical axis, as shown below. Figure 5As shown. The groove of retaining member 7 is also configured such that its dimension in the radial direction is substantially the same as the cross-sectional diameter of elastic member 8 in the direction orthogonal to the optical axis (in the radial direction).

[0090] The groove of retaining member 7 clamps and holds elastic member 8, for example, so that when assembling optical device 100 or lens module 2, the mounting position of elastic member 8 does not shift (does not move) or elastic member 8 does not disengage. The groove can be, for example, a recess (including concave and equivalent shapes) or a semicircle, and can be of any shape as long as the position of elastic member 8 does not shift when it is placed in the groove. The groove can also be provided on the first optical element 5, in which case the groove may not be provided on retaining member 7. In the third embodiment, retaining member 7 is made of metal or resin material.

[0091] The elastic member 8 is made of a rubber material such as silicone rubber and is integrally formed into a ring shape. When in contact with the peripheral portion of the first optical element 5, the elastic member 8 contacts the entire circumference of the first optical element 5 because it is integrally formed into a ring shape. The elastic member 8 preferably has an integrally formed ring shape as described above, but it may also have a ring shape that contacts, for example, a portion of the first optical element 5. Alternatively, the elastic member 8 may be composed of three elastic members that contact the first optical element 5 at predetermined intervals (e.g., 120-degree intervals). During the assembly of the lens module 2, the elastic member 8 is sandwiched and held between the first optical element 5 and the retaining member 7.

[0092] Despite Figure 4 and Figure 5 Although not shown in the diagram, the control unit of the optical device 100 according to the third embodiment is composed of at least one computer including a CPU, a memory (storage unit), etc., and is connected to each component of the optical device 100 via a circuit. The control unit controls the overall operation adjustment, etc., of all components of the optical device 100 according to a computer program stored in the memory. Similar to the first embodiment, this control will be described later. Figure 11 The flowchart shown illustrates the operation. For example, the control unit is preferably configured integrally with other parts of the optical device 100 (e.g., housing 3), but it can also be configured separately from other parts of the optical device 100.

[0093] A control unit (not shown) controls the light source unit, movable mirror, light receiving element, etc. Specifically, the control unit drives the light source unit and movable mirror with a predetermined driving voltage and driving frequency, and measures the waveform of the light received by the light receiving element at a specific frequency. Then, the control unit measures the difference between the time when the light receiving element receives light and the time when light is emitted from the light source unit, or measures the difference between the phase of the light received signal acquired by the light receiving element and the phase of the output signal from the light source unit, and multiplies this difference by the speed of light to determine the distance to the object. The control unit of the third embodiment may be the same as the control unit 14 of the first or second embodiment.

[0094] Next, the process for holding the first optical element 5 and the other optical element 6 in the lens barrel 4 will be described. First, the elastic member 8 is inserted and clamped in the groove of the retaining member 7, such that the elastic member 8 is held by the retaining member 7. Next, the other optical element 6 is inserted into the lens barrel 4. Next, the first optical element 5 is inserted, and the planar portion of the protrusion receiving portion 5a of the first optical element 5 abuts against the planar portion of the protrusion 7a of the retaining member 7.

[0095] Then, the internal threaded portion 7b of the retaining member 7 is screwed together with the external threaded portion 4a of the lens barrel 4, such that when the planar portion of the protrusion 7a and the planar portion of the protrusion receiving portion 5a abut (engage) each other in a direction orthogonal to the optical axis (in the radial direction), the retaining member 7 and the lens barrel 4 are fixed. Therefore, when the first optical element 5, the retaining member 7, and the elastic member 8 rotate about the optical axis in the rotational direction (circumferential direction), they rotate as a single unit.

[0096] With the above-described structure, the elastic member 8 can be held in place while preventing torsional or twisting deformation of the elastic member 8 that may be caused by friction between the elastic member 8 and the first optical element 5 in contact with the elastic member 8 and the holding member 7. Thus, the holding member 7 can hold (press) the peripheral portion of the first optical element 5 with a uniform force via the elastic member 8.

[0097] In the third embodiment, for example, the coefficient of linear expansion is 26 × 10⁻⁶. -6 Aluminum alloys with a temperature of / ℃ can be used for the lens barrel 4, retaining member 7, and spacer (not shown). The first optical element 5 and the other optical element 6 use an aluminum alloy with a linear expansion coefficient of 7×10⁻⁶. -6 Glass material at / ℃.

[0098] Here, as an example, assume that there is a spacer with a thickness of 5 mm in another optical element 6, and that the distance between the receiving portion on the R1 surface of the first optical element 5 and the supporting portion 4b of the lens barrel 4 in the optical axis direction is 25 mm. The receiving portion on the R1 surface of the first optical element 5 is the portion of the first optical element 5 that contacts the elastic member 8.

[0099] At this time, when the temperature changes by 1°C, a thermal expansion difference of approximately 0.29 μm occurs between the receiving portion on the R1 surface of the first optical element 5 and the supporting portion 4b of the lens barrel 4. That is, a gap difference of approximately 0.29 μm occurs between the lens barrel 4 and the first optical element 5. Therefore, for example, when the optical device 100 is placed in an external environment (e.g., outdoors), in an environment where the ambient temperature and the internal temperature of the optical device 100 are 60°C higher than the temperature at which the optical device 100 was assembled, approximately 17.4 μm of loosening (loosening amount) occurs in the optical axis direction. On the other hand, in an environment where the ambient temperature is 60°C lower than the temperature at which it was assembled, as described above, approximately 17.4 μm of lens (optical element) deformation occurs in the optical axis direction.

[0100] In the third embodiment, the elastic member 8, which is disposed in the groove of the retaining member 7, contacts the first optical element 5, and presses the first optical element 5 along the optical axis, elastically deforms to absorb the loosening in the optical axis direction as described above. That is, in an environment where the ambient temperature is 60°C higher or lower than the temperature when assembling the optical device 100, the length of the optical element changes by approximately 11.4 μm in the optical axis direction, but the deformation of the optical element can be absorbed by the elastic member 8.

[0101] Furthermore, the elastic member 8 is held in such a way that the first optical element 5, the retaining member 7, and the elastic member 8 can rotate around the optical axis as a single unit, thereby preventing torsional or twisting deformation of the elastic member 8 that may be caused by friction. In the third embodiment, the surface of the protrusion receiving portion 5a that abuts against the planar surface of the protrusion 7a is also formed into a planar shape as described above, making the shape easy to process. However, the shapes of the protrusion receiving portion 5a and the protrusion 7a are not limited to these, and can also be, for example... Figure 6 The shape shown.

[0102] Figure 6 It is an exploded perspective view of retaining member 27, elastic member 28 and first optical element 25. Figure 6 The components shown are Figure 4 and Figure 5 The difference in the components shown lies in the shape of the protrusions and the protrusion receiving portion; therefore, descriptions of the same parts as those described above will be omitted.

[0103] like Figure 6 As shown, the protrusion (joint portion) 27a of the retaining member 27 is formed to have a rectangular cross-section in a direction orthogonal to the optical axis. Furthermore, the protrusion 27a is formed to protrude a predetermined length in the optical axis direction. The protrusion receiving portion 25a of the first optical element 25 is also formed on the first optical element 25 in a shape corresponding to the protrusion 27a. For example, Figure 6 In the example, the protruding receiving portion 25a is formed to have a concave cross-section in a direction orthogonal to the optical axis.

[0104] Despite Figure 6 The central protrusion 27a has a rectangular cross-sectional shape in the radial direction, but it can also be a shape other than a rectangle, such as a triangle or trapezoid. In this case, the protrusion receiving portion 25a has a shape corresponding to that of the protrusion 27a. Although in Figure 6 The protruding receiving portion 25a radially abuts (engages) the protrusion 27a, but the depth of the groove in the protruding receiving portion 25a may be greater than the thickness of the protrusion 27a. That is, the protrusion 27a and the protruding receiving portion 25a only need to engage with each other in the radial or circumferential direction.

[0105] In the optical device 100 of the third embodiment described above, the first optical element 5 (25), the holding member 7 (27), and the elastic member 8 (28) are rotated as a single unit, thereby holding the elastic member 8 while preventing twisting or distortion of the elastic member 8. Therefore, an optical device 100 can be provided that can hold the first optical element 5 with a uniform force via the elastic member 8 through the holding member 7.

[0106] Although it has been assumed that the optical device 100 according to the third embodiment is applied to an in-vehicle camera for driving assistance or autonomous driving, the present invention is not limited thereto and can also be applied to an optical device for an in-vehicle camera.

[0107] Fourth embodiment

[0108] The third embodiment has been described with reference to an example in which a protrusion receiving portion 5a corresponding in shape to the protrusion 7a is provided on the outer diameter portion of the optical element (first optical element 5). The fourth embodiment will be described with reference to a lens module (lens holding mechanism) in which a protrusion receiving portion is provided on the portion of the optical element (first optical element 5) other than its outer diameter. Matters not mentioned in the fourth embodiment are consistent with those in the third embodiment.

[0109] Figure 7 This is a cross-sectional view of the lens module 22 according to the fourth embodiment. Figure 8 This is an example of an exploded perspective view of the first optical element 35, the retaining member 37, and the elastic member 38 according to the fourth embodiment.

[0110] In the fourth embodiment, the first optical element 35 is constructed as a resin-molded lens. The retaining member 37 is also constructed as a resin-molded component. By constructing the first optical element 35 and the retaining member 37 as resin-molded components, the manufacturing cost or component cost of the first optical element 35 and the retaining member 37 can be reduced, and they can be processed into highly flexible shapes during processing, etc.

[0111] The lens barrel 34 has an internal threaded portion 34a and a support portion 34b. In the fourth embodiment, the lens barrel 4 is made of metal or resin. The internal threaded portion 34a is a threaded portion formed along the inner circumference of the lens barrel 34 on a portion of the cylindrical or conical inner surface of the lens barrel 34. The support portion 34b is a surface perpendicular to the optical axis (orthogonal to the optical axis), facing a side surface in the optical axis direction of another optical element 36, and this support portion supports the first optical element 35 and the other optical element 36. Here, the support portion 34b is not limited to a surface perpendicular to the optical axis; it can also be a surface inclined relative to the optical axis.

[0112] The first optical element 35 has a protruding receiving portion (joined portion) 35a. The protruding receiving portion 35a is disposed between the outer side of the effective diameter of the first optical element 35 and the inner side of its outer diameter. Each protruding receiving portion 35a is configured in a shape corresponding to each protrusion 37a, and in the fourth embodiment, its cross-section in the direction orthogonal to the optical axis is formed as a circle. Each protruding receiving portion 35a is configured as a hole, the size of which allows the protrusion 37a to be inserted into the hole when assembling the lens module 22. Although in Figure 8 In the example shown, three protrusions 37a are provided on the first optical element 35, but the invention is not limited to this, and at least one or more protrusions 37a may be formed. Protrusion receiving portions 35a are formed according to the number and position of the protrusions 37a. The number of protrusion receiving portions 35a is preferably the same as the number of protrusions 37a, but may also be greater than the number of protrusions 37a.

[0113] The retaining member 37 has a protrusion (engaging portion) 37a and an externally threaded portion 37b. Each protrusion 37a has a circular cross-section in a direction orthogonal to the optical axis and protrudes a predetermined length in the optical axis direction. That is, each protrusion 37a in the fourth embodiment is configured as follows: Figure 8 The cylindrical shape shown.

[0114] The length of the protrusion 37a in the optical axis direction is set such that it does not protrude beyond the end of the first optical element 35 on the side of the other optical element 36 when the lens module 22 is assembled. Therefore, the length of the protrusion 7a in the optical axis direction can be arbitrarily set, as long as it does not protrude from the end of the first optical element 35 on the side of the other optical element 36. The protrusion receiving portion 35a does not need to be a through hole, but only needs to be formed to be longer than the protruding length of the protrusion 37a in the optical axis direction.

[0115] The external thread portion 37b is a threaded portion formed along the outer periphery of the retaining member 37 on a portion of the cylindrical or conical outer surface of the retaining member 37. By... Figure 7 The internal thread portion 34a and the external thread portion 37b shown are screwed together to assemble and fix the retaining member 37 to the lens barrel 34.

[0116] The elastic member 38 is made of a rubber material such as silicone rubber and is integrally formed into a ring shape. In the fourth embodiment, the elastic member 38 is located outside the protrusion 37a in a direction orthogonal to the optical axis and is held by the retaining member 7 such that the inner surface of the elastic member 38 contacts the outer surface of the protrusion 37a.

[0117] Next, the process for holding the first optical element 35 and the other optical element 36 in the lens barrel 34 will be described. First, the elastic member 38 is inserted such that the inner surface of the elastic member 38 contacts the outer surface of the protrusion 37a of the retaining member 37. Next, the other optical element 36 is inserted into the lens barrel 34. Next, the first optical element 35 is inserted. Next, the protrusion 37a of the retaining member 37 holding the elastic member 38 is inserted into the protrusion receiving portion 35a of the first optical element 35. Next, the external threaded portion 37b of the retaining member 37 is screwed into the internal threaded portion 34a of the lens barrel 34, such that the retaining member 37 and the lens barrel 34 are fixed when the protrusion 37a and the protrusion receiving portion 35a are adjacent to each other (engaged). Therefore, when the first optical element 35, the retaining member 37, and the elastic member 38 rotate about the optical axis in the rotational direction (circumferential direction), they rotate as a single unit.

[0118] Using the above-described structure, the elastic member 38 can be held in place while preventing it from twisting or deforming. Therefore, an optical device 100 can be provided in which the holding member 37 can hold (press) the first optical element 35 with a uniform force via the elastic member 38, similar to the third embodiment.

[0119] Despite Figure 8The protruding receiving portion 35a is a circular hole and engages with the protrusion 37a in the radial direction, but the protruding receiving portion 35a can also be an elongated hole extending in the radial direction. That is, the protrusion 37a and the protruding receiving portion 35a only need to engage with each other in the radial or circumferential direction. Furthermore, although it has been assumed that the optical device 100 according to the third or fourth embodiment will be applied to an in-vehicle camera for driving assistance or autonomous driving, the present invention is not limited thereto and can also be applied to devices other than in-vehicle cameras.

[0120] Fifth embodiment

[0121] Figure 9 This is a construction diagram of the optical device 100 and the vehicle system (driving assistance device) 1000 including the optical device 100 according to each of the above embodiments. The vehicle system 1000 is held by a movable moving body (moving device) such as a car (vehicle) and is a control system for assisting the driving (steering) of the vehicle 500 based on distance information of objects (e.g., obstacles and pedestrians) around the vehicle acquired by the optical device 100. Figure 10 This is a schematic diagram of a vehicle 500, which includes an onboard system 1000, as a mobile device. Although Figure 10 The example shown illustrates a scenario where the distance measurement range (detection range) 50 of the optical device 100 is positioned in front of the vehicle 500, but the distance measurement range 50 can also be positioned behind or to the side of the vehicle 500.

[0122] like Figure 9 As shown, the vehicle system 1000 includes an optical device 100, a vehicle information acquisition device 200, a control device (control unit or electronic control unit (ECU)) 300, and a warning device (warning unit) 400. The control unit 14 according to the first or second embodiment, or the control unit (not shown) according to the third or fourth embodiment, included in the optical device 100 of the vehicle system 1000, has functions corresponding to the distance acquisition unit (acquisition unit) and the collision determination unit (determination unit). However, if desired, the vehicle system 1000 may have a distance acquisition unit and a collision determination unit separate from the control unit, and the distance acquisition unit and the collision determination unit may be located outside the optical device 100 (e.g., inside the vehicle 500). Alternatively, the control device 300 may be used as the control unit 14 according to the first or second embodiment, or as the control unit (not shown) according to the third or fourth embodiment.

[0123] Figure 11 This is a flowchart illustrating exemplary operation of the vehicle system 1000 according to the fifth embodiment. The operation of the vehicle system 1000 will now be described with reference to this flowchart.

[0124] First, in step S1, an object (obstacle) surrounding the vehicle 500 is illuminated using a laser emitted by the light source forming unit of the optical device 100, and reflected light from the object is received. The control unit acquires distance information of the object based on the signal output by the light receiving element (light receiving unit) when it receives the reflected light. At this time, the distance acquisition unit is configured as a distance information acquisition unit that acquires distance information of the object based on the signal from the light receiving element. Here, the distance information may be information related to the distance from the moving device (vehicle 500) to the object, and may not be the distance itself. In step S2, the vehicle information acquisition device 200 acquires vehicle information including the vehicle speed, yaw rate, steering angle, etc. of the vehicle 500. 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.

[0125] Therefore, it can be determined whether an object exists within a set distance range around the vehicle 500, and the probability of a collision between the vehicle 500 and the object can be determined. Steps S1 and S2 can be executed in the reverse order described above, or they can be executed in parallel. If an object exists within the set distance range, the control unit determines that "there is a possibility of a collision" (step S4); if no object exists within the set distance range, the control unit determines that "there is no possibility of a collision" (step S5).

[0126] Next, upon determining that a collision is possible, the control unit reports (sends) 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 control unit's determination result (step S6), and the warning device 400 warns the user (driver or passenger) of the vehicle 500 based on the control unit's determination result (step S7). At this time, the warning device 400 functions as a warning unit configured to issue a warning based on the distance information of the object. The determination result only needs to be reported to at least one of the control device 300 and the warning device 400.

[0127] The control device 300 serves as a control unit configured to control the driving and movement of the vehicle 500 by outputting control signals to the drive unit (e.g., engine or motor) of the vehicle 500. The control device 300 performs controls on the vehicle 500, such as braking, releasing the accelerator, turning the steering wheel, and generating control signals to apply braking force to each wheel to limit the output of the engine or motor. The warning device 400 warns the user, for example, by issuing a warning sound, displaying a warning message on the screen of the car navigation system, or vibrating the seatbelt or steering wheel.

[0128] As described above, the vehicle system 1000 according to the fifth embodiment can detect and measure objects through the above-described process to avoid collisions between the vehicle 500 and the objects. In particular, by applying the optical device 100 according to each of the above embodiments to the vehicle system 1000, high-precision distance measurement can be achieved, thereby enabling object detection and collision determination to be performed with high precision.

[0129] Although the vehicle system 1000 is applied to driver assistance (damage mitigation in collisions) in the fifth embodiment, the vehicle system 1000 is not limited to this and can also be applied to cruise control (including full-speed range adaptive cruise control), autonomous driving, etc. The vehicle system 1000 can be applied not only to vehicles such as automobiles, but also to mobile bodies such as ships, aircraft, and industrial robots. The vehicle system 1000 can be applied not only to mobile bodies, but also to various devices that use object recognition, such as intelligent transportation systems (ITS) and surveillance systems.

[0130] The vehicle system 1000 or vehicle 500 may be equipped with a reporting device (reporting unit) that reports the fact to the vehicle system manufacturer, mobile device distributor, etc., if the vehicle 500 collides with an obstacle. This reporting device may be, for example, a device that sends information about the collision between the vehicle 500 and the obstacle (collision information) to a preset external reporting destination via email.

[0131] By employing a reporting device to automatically report collision information in this manner, measures such as inspection and repair can be taken quickly after a collision. The destination for reporting collision information can be an insurance company, medical institution, police, or any other party set by the user. Furthermore, the reporting device can also be configured to report not only collision information to the reporting destination but also malfunction information of individual components or consumption information of consumables. The presence of a collision can be detected using distance information acquired based on the output of the light receiving element 8 according to the first or second embodiment described above, or from the light receiving element (not shown) according to the third or fourth embodiment, or by using other detection units (sensors).

[0132] A computer program implementing the functions of the above embodiments can be provided to the optical device 100, etc., via a network or various storage media to perform some or all of the controls described in the above embodiments. The computer (or CPU, MPU, etc.) of the optical device 100, etc., can then read and execute the program. In this case, the program and the storage medium storing the program constitute the present invention.

[0133] Although the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims should be interpreted in the broadest sense to cover all variations and equivalent structures and functions.

[0134] This application claims the benefits of Japanese Patent Application No. 2022-055910, filed on March 30, 2022, and Japanese Patent Application No. 2022-055284, filed on March 30, 2022, which are incorporated herein by reference in their entirety.

Claims

1. A lens holding mechanism, comprising: A lens barrel configured to house a lens; A pressure ring, the pressure ring being configured to move relative to the lens barrel in a direction along the optical axis; A rotating ring configured to rotate about the optical axis to move the pressure ring in a direction along the optical axis; as well as An elastic member is disposed between the lens and the pressure ring. The lens barrel is characterized by having a rotation limiting part and a movement limiting part. The rotation limiting part is configured to limit the rotation of the pressure ring about the optical axis, and the movement limiting part is configured to limit the movement of the pressure ring along the optical axis. In this process, by moving the pressure ring in a direction along the optical axis, the elastic member is biased against the peripheral portion of the lens in the same direction.

2. The lens holding mechanism according to claim 1, characterized in that, The elastic member is held by the pressure ring by being fitted into a recess formed on the pressure ring.

3. The lens holding mechanism according to claim 1, characterized in that, The pressure ring and the rotating ring are connected together by threads.

4. A lens holding mechanism, comprising: A lens barrel configured to house a lens; A sensor holder configured to hold an image pickup element in a fixed position and movable relative to the lens barrel in a direction along the optical axis; A rotating ring configured to rotate about the optical axis to allow the sensor holder to move in a direction along the optical axis; as well as An elastic member is disposed between the lens and the sensor holder. The lens barrel is characterized by having a rotation limiting part and a movement limiting part. The rotation limiting part is configured to limit the rotation of the sensor holder about the optical axis, and the movement limiting part is configured to limit the movement of the sensor holder in the direction along the optical axis. In this process, by moving the sensor holder in a direction along the optical axis, the elastic member is biased against the peripheral portion of the lens in the same direction.

5. The lens holding mechanism according to claim 4, characterized in that, The elastic member is held by the sensor holder by being fitted into a recess formed on the sensor holder.

6. The lens holding mechanism according to claim 4, characterized in that, The sensor holder and the rotating ring are threaded together.

7. An optical device, comprising: A scanning unit configured to scan an object using illumination light from a light source; as well as The lens holding mechanism according to any one of claims 1 to 6, The feature is that the reflected light from the object illuminated by the scanning unit is guided to the light receiving element via the lens.

8. A control system, comprising: The optical device according to claim 7; as well as A distance acquisition unit, characterized in that the distance acquisition unit is configured to acquire distance information of the object based on a signal from the optical receiving element.

9. The control system according to claim 8, characterized in that, The control system further includes a control device configured to control the movement of the device based on the distance information of the object.

10. The control system according to claim 8, characterized in that, The control system further includes a warning device configured to issue a warning based on the distance information of the object.

11. A mobile device, the mobile device comprising the optical device according to claim 7, characterized in that, The moving device is movable and configured to hold the optical device.

12. The mobile device according to claim 11, characterized in that, The mobile device also includes a control unit configured to control the movement of the mobile device based on distance information of the object.

13. The mobile device according to claim 11, characterized in that, The mobile device also includes a warning unit configured to issue a warning based on distance information of the object.

14. A lens holding mechanism, the lens holding mechanism being configured to include: A lens barrel configured to house multiple optical elements; A retaining member configured to assemble with the lens barrel and press the first optical element among the plurality of optical elements in a direction along the optical axis; as well as An elastic member is disposed between the first optical element and the retaining member. The characteristic feature is that a joining portion is formed on the retaining member, and The first optical element has a joined portion, which is configured to engage with the joining portion in the radial or circumferential direction. The first optical element, the retaining member, and the elastic member are configured to rotate integrally with each other in the circumferential direction.

15. The lens holding mechanism according to claim 14, characterized in that, The joining portion and the joined portion have planar portions, and The planar portions of the joining portion and the planar portions of the joined portion are joined to each other in the radial or circumferential direction.

16. The lens holding mechanism according to claim 14, characterized in that, The joining portion has a protrusion configured to project in a direction along the optical axis.

17. The lens holding mechanism as claimed in claim 14, characterized in that, The elastic member is held by the retaining member by being fitted into a recess formed on the retaining member.

18. The lens holding mechanism according to claim 14, characterized in that, The lens barrel and the retaining member are threaded together.

19. The lens holding mechanism according to claim 14, characterized in that, The elastic member abuts against the retaining member and the first optical element in the direction along the optical axis.

20. An optical device, comprising: A scanning unit configured to scan an object using illumination light from a light source; as well as The lens holding mechanism according to any one of claims 14 to 19, The characteristic feature is that the reflected light from the object illuminated by the scanning unit is guided to the light receiving element via the optical element.

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