Lens device, optical device, image capturing device, in-vehicle system, and mobile device

Abstract

To provide a lens device capable of reducing misalignment of lenses associated with temperature changes while minimizing an increase in size.SOLUTION: A lens device is provided, comprising a lens barrel for accommodating multiple lenses, a retaining member in contact with at least one of the multiple lenses, a pressed part in contact with the retaining member, and an elastic member sandwiched between the pressed part and the lens barrel in an optical axis direction, where the pressed part is located on the inside of the retaining member and on the outside of the lens barrel in a radial direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a lens apparatus, an optical apparatus, an imaging apparatus, an in-vehicle system, a moving apparatus, and the like. [Background technology]

[0002] For example, optical devices installed in automobiles include cameras that capture images of the surroundings of the automobile and are used for driving assistance and autonomous driving. Another optical device with a sensing function is LiDAR (Light Detection And Ranging).

[0003] These devices have a lens barrel that holds a lens as an optical element. When a lens is held in the barrel, if the environmental temperature changes due to the difference in the amount of expansion and contraction caused by the difference in the linear expansion coefficient between the lens and the barrel, a gap (backlash) or tightness may occur in the optical axis direction.

[0004] Changes in the holding position due to the generated backlash and deformation of the lens surface due to the generated tightening can cause deterioration of optical performance and deterioration of parts over time. In-vehicle cameras and LiDAR are required to guarantee excellent performance and functionality over the entire temperature range in a wide range of changing temperature environments.

[0005] Furthermore, in-vehicle cameras usually do not include an autofocus mechanism for reasons of cost and reliability to prevent breakdowns. Driving assistance and autonomous driving functions of automobiles are required to have higher performance and functionality than currently available, and the optical system of the in-vehicle camera, which serves as the eyes of the automobile, is required to become more complex and have higher functionality.

[0006] As the optical system of an in-vehicle camera becomes more complex and highly functional, the number of optical elements also increases, and the backlash and tightening between the presser ring, lens barrel, and lens caused by temperature changes can become even larger. To address this, there is a configuration in which an elastic member is sandwiched between the presser ring and the lens, and is compressed by a required amount in advance during assembly at room temperature to provide elasticity and eliminate backlash at high temperatures.

[0007] In addition, vehicle-mounted cameras are used to monitor the front, surroundings, and rear of a vehicle, and generally, in order to save space, a wide angle of view is desired in order to obtain a large amount of information from a single camera. In Patent Document 1, a leaf spring is provided in the pressing ring that holds the lens, and the pressure of the leaf spring is used to prevent play in the optical axis direction caused by temperature changes. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 5049220 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the above conventional example, a radial length is required to provide elastic force to the leaf spring. Also, when the elastic member is held between the press ring and the lens, the elastic member needs to be located at a position radially away from the effective diameter of the lens in order to ensure a wide viewing angle. In other words, the press ring may become large in the radial direction.

[0010] Furthermore, in wide-angle cameras, the radial size of the lens closest to the subject tends to be large. In addition, if the pressing ring also needs to be long in the radial direction, the diameter of the lens barrel unit (lens device) including the pressing ring may become large. If the diameter of the lens barrel unit on the subject side becomes large, when the camera is installed close to the windshield that slopes from the front to the rear of the vehicle, specifying the installation height may result in the entire camera being positioned backward, which may increase the installation space.

[0011] Furthermore, if there is a gap between the windshield and the lens, light from below the camera may be reflected by the windshield and enter the lens. When light reflected by the windshield enters the lens, an image of that light will be reflected in the image captured by the camera. To prevent this, for example, a reflection prevention hood is provided that extends from below the camera toward the windshield.

[0012] Because the diameter of the lens barrel unit on the subject side becomes larger, the entire camera must be installed backward, and this anti-reflection hood must be extended further toward the windshield, which can result in an increase in the size of the entire camera unit.

[0013] SUMMARY OF THE PRESENTLY PREFERRED EMBODIMENTS An object of the present invention is to provide a lens device that can reduce lens position deviation caused by temperature changes while preventing an increase in size. [Means for solving the problem]

[0014] In the lens device, a lens barrel housing a plurality of lenses; a pressing member that contacts at least one of the lenses; A biased portion that contacts the pressing member; an elastic member that is sandwiched between the biased portion and the lens barrel in the optical axis direction; The biased portion is disposed radially inside the pressing member and outside the lens barrel. Effect of the Invention

[0015] According to the present invention, it is possible to realize a lens device that can reduce lens position deviation caused by temperature changes while suppressing an increase in size. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of an optical device 101 according to a first embodiment. [Diagram 2]2 is a cross-sectional view showing an example of the structure of a barrel unit 102 according to the first embodiment. [Diagram 3] 1 is a cross-sectional view of lens barrel 17 of embodiment 1 when it is brought into contact with biased portion 19 of pressing member 18. FIG. [Figure 4] 10 is a cross-sectional view illustrating an example of the structure of a barrel unit 202 according to the second embodiment. [Diagram 5] 13 is a cross-sectional view of barrel unit 202 in the case where a biased member is fixed to a pressing member by screwing it with a screw, according to the second embodiment. FIG. [Figure 6] 11 is a cross-sectional view illustrating the structure of a barrel unit 302 according to the third embodiment. FIG. [Figure 7] 10 is a cross-sectional view illustrating the structure of a barrel unit 303 according to a fourth embodiment. [Figure 8] 13 is a cross-sectional view illustrating the structure of a barrel unit 304 according to the fifth embodiment. FIG. [Figure 9] FIG. 13 is a schematic diagram of an imaging device according to a sixth embodiment. [Figure 10] 13(A) and (B) are a schematic diagram of a moving device according to a sixth embodiment and a diagram showing optical characteristics of an optical system. [Figure 11] FIG. 13 is a functional block diagram showing a configuration example of an in-vehicle system according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment. In each drawing, the same members or elements are given the same reference numerals, and duplicated descriptions are omitted or simplified.

[0018] <Embodiment 1> 1 is a schematic diagram of an optical device 101 of embodiment 1. The optical device 101 is composed of a barrel unit (lens device) 102, a housing 103 that holds the barrel unit 102, and an electric device 104. For example, when the optical device 101 is an on-vehicle camera, the barrel unit 102 functions as an imaging optical system, and when an image of a subject 105 is captured, a signal is input to the electric device 104 that includes an image sensor, thereby acquiring environmental information about the surroundings of the vehicle.

[0019] The image sensor is, for example, a CCD or CMOS image sensor, and converts the image formed by condensing light through the lens barrel unit 102 into an electrical signal. The converted electrical signal is then converted into digital image data, etc., and used in driving assistance and autonomous driving systems.

[0020] Furthermore, the lens barrel unit 102 of the optical device 101 such as an in-vehicle camera may be installed on the vehicle body close to the windshield 106 with a part of the lens barrel unit as a lens device exposed from the housing, and the lens facing the subject side from the housing 103. Furthermore, if there is a gap between the windshield 106 and the lens barrel unit 102, light from below the optical device 101 may be reflected by the windshield 106 and enter the lens barrel unit 102.

[0021] When light reflected by the windshield 106 enters the lens, an image formed by that light is reflected on the image sensor through the lens barrel unit 102. To prevent this reflection, an anti-reflection hood (not shown) is provided extending from below the optical device 101 toward the windshield 106.

[0022] 2 is a cross-sectional view showing an example of the structure of barrel unit 102 of embodiment 1. Barrel unit 102 includes a barrel 17 that houses, for example, a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens 15 as multiple lenses from the subject side (the left side in FIG. 2). In addition, barrel 17 has a spacer 16 that is arranged between the third lens 13 and the fourth lens 14.

[0023] Furthermore, it has a pressing member 18 and an elastic member 20 that contact the subject side of the first lens 11 to hold the first lens 11 on the lens barrel 17. That is, the pressing member 18 contacts at least one of the multiple lenses. In this embodiment, the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15 are, for example, glass lenses. Also, the spacer 16, the lens barrel 17, and the pressing member 18 are made of a metal material.

[0024] The number of lenses, the number of spacers, and the materials of the lenses, spacers, and lens barrel can be set arbitrarily according to the application, etc. For example, the first lens 11 may be a spherical glass lens, and the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15 may be resin lenses. In addition, the pressing member 18 may also be made of a resin material.

[0025] Such a lens barrel unit 102 may be provided with an "aperture diaphragm" that limits the amount of transmitted light and determines the F-number, which is an index of brightness, or a "light blocking diaphragm" that blocks light rays that cause ghosts and light rays that cause aberrations. However, in this embodiment, these are omitted. Note that an anti-reflection film, a hydrophilic film, a water-repellent film, etc. are provided on the surfaces of these first lens 11, second lens 12, third lens 13, fourth lens 14, and fifth lens 15 as necessary.

[0026] Elastic member 20 is made of a rubber material such as silicone rubber that takes heat resistance into consideration so that its physical properties are not affected even in a severe vehicle temperature environment, or a spring made of a metal material such as a compression coil spring or a wave washer. Elastic member 20 is sandwiched and held in the optical axis O direction by biased portion 19 provided on lens barrel 17 and pressing member 18.

[0027] Here, we will explain how to assemble the lens barrel unit 102. The lens barrel unit 102 houses and holds the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 15, and the spacer 16 inside the lens barrel 17. Next, in this state, the elastic member 20 and the pressing member 18 provided with the biased portion 19 are inserted from the side opposite the subject side, and the lens barrel mating portion 17a and the pressing member mating portion 18a are mated by, for example, caulking.

[0028] That is, with elastic member 20 compressed, the subject-side tip of pressing member 18 is, for example, roller crimped or thermally crimped to fix first lens 11 to lens barrel 17 in the direction of optical axis O. By holding first lens 11 with pressing member 18 with elastic member 20 compressed by the required amount, first lens 11 is constantly pressed against pressing member 18 by the reaction force due to the elastic force of elastic member 20.

[0029] An optical system with a wide viewing angle has a feature that, among multiple lenses, first lens 11, which is closest to the subject, has a larger outer diameter size than the other lenses. By arranging elastic member 20 on the image plane side (opposite the subject side) of first lens 11 via lens barrel 17, pressing member 18 can press first lens 11 without increasing the outermost diameter of lens barrel unit 102 including pressing member 18.

[0030] In addition, even if the elastic member 20 is twisted or compressed in a direction perpendicular to the optical axis O during assembly, the elastic member 20 does not exceed the engagement gap between the lens barrel engagement portion 17a and the presser member engagement portion 18a because the lens barrel engagement portion 17a and the presser member engagement portion 18a are engaged. Therefore, the lens can be stably pressed in the optical axis O direction.

[0031] Furthermore, because the pressing member 18 constantly presses the first lens 11 with the reaction force due to the elastic force of the elastic member 20, when the environmental temperature drops from the time of assembly, the deformation of the lens caused by tightening resulting from the difference in linear expansion coefficient between the lens barrel 17 and the lens can be absorbed by the elastic member 20.

[0032] In this embodiment, the lens barrel 17, the pressing member 18, and the spacer 16 are made of an aluminum alloy, and have a linear expansion coefficient of 26×10^-6 / °C. The first lens 11, the second lens 12, the third lens 13, the fourth lens 14, and the fifth lens 15 are made of glass, and have a linear expansion coefficient of 7×10^-6 / °C.

[0033] The length of spacer 16 in the optical axis direction is 1.5 mm, and the length in the optical axis direction from wall portion 17b of lens barrel 17 to the contact portion of pressing member 18 with first lens 11 is 10 mm. The optical axis thicknesses of second lens 12, third lens 13, fourth lens 14, and fifth lens 15 are each 1 mm. In this case, a 1°C change in temperature causes a difference in the gap between the lens barrel and the lenses of 0.16 μm.

[0034] Therefore, in an environment where the outside air temperature drops by 60° C. from the time of assembly, the lens will deform by 9.7 μm in the optical axis direction, but the elastic member 20 can absorb this deformation.

[0035] On the other hand, in an environment where the outside air temperature rises by 60°C from the time of assembly, a backlash of 9.7 μm will occur in the optical axis direction. However, by assembling the lens in a state where the elastic member 20 is compressed by the required amount, the pressing member 18 constantly presses and holds the first lens 11 with the reaction force of the elastic force of the elastic member 20, so this backlash can be absorbed.

[0036] Fig. 3 is a cross-sectional view of the lens barrel 17 of the first embodiment when it is brought into contact with the urged portion 19 of the pressing member 18. That is, in Fig. 3, a part of the urged portion 19 on the subject side is held in contact with the lens barrel in the optical axis direction. By assembling the lens barrel 17 in a compressed state until it is brought into contact with the urged portion 19, it is possible to impart a certain elastic force to the elastic member 20.

[0037] The compression amount of the elastic member 20 is set so as to absorb the amount of tightening and the amount of backlash that occurs when temperature changes, in addition to the machining dimensional tolerances of the optical axis O direction components of the first lens 11, the second lens 12, the third lens 13, the fourth lens 14, the fifth lens 15, the lens barrel 17, and the spacer 16. This allows the elastic force of the elastic member 20 and the pressing member 18 to constantly and stably press the first lens 11. Also, the inner diameter position of the elastic member 20 is determined by the outer diameter of the lens barrel 17. This guides the radial position of the elastic member 20, improving the stability of assembly.

[0038] In this embodiment, by arranging elastic member 20 on the image plane side of first lens 11 via lens barrel 17, the elements that determine the radial size of lens barrel unit 102 are only the thickness of first lens 11 and lens barrel 17 and the thickness of retaining member 18. This makes it possible to hold the lens without increasing the size, even in an optical system with a wide field of view.

[0039] 1, when optical device 101 in which a part of the outer diameter part of the lens barrel unit 102 is exposed is installed on a vehicle body, for example, it can be installed close to windshield 106. This makes it possible to reduce the installation space for optical device 101 on the vehicle body.

[0040] Furthermore, by making the optical device 101 smaller, it becomes possible to install an anti-glare hood (not shown) that extends from below the optical device 101 toward the windshield 106 without increasing its size.

[0041] As described above, this embodiment comprises a lens barrel 17 that houses a plurality of lenses, and a pressing member 18 that holds the lens to the lens barrel 17 by contacting the subject side of the lens, and is provided with a biased portion 19 that contacts the pressing member 18.

[0042] The urged portion is disposed radially inside the pressing member and outside the lens barrel, and an elastic member 20 is provided that is sandwiched between the urged portion and the lens barrel in the optical axis direction. That is, the elastic member 20 is disposed so as to be sandwiched between the pressing member 18 and the lens barrel 17 in the radial direction of the lens barrel 17, and the elastic member 20 is configured to be sandwiched between the lens barrel 17 and the urged portion 19 in the optical axis O direction.

[0043] Also, as described above, by assembling the elastic member 20 in a compressed state, it becomes possible for the lens to be held in a state where it is constantly pressed against the pressing member 18 by the reaction force due to the elastic force of the elastic member 20. With this configuration, the elastic member 20 absorbs the tightening and backlash that occurs on the lens due to differences in the linear expansion coefficient when the temperature of the lens-barrel unit 102 changes, and it is possible to hold the lens by applying a constant pressure.

[0044] <Embodiment 2> In the first embodiment, an example of a configuration in which the pressing member and the urged portion are integrated has been described, but as the second embodiment, a lens barrel unit in which the pressing member and the urged portion are configured as separate parts will be described.

[0045] 4 is a cross-sectional view illustrating an example of the structure of barrel unit 202 according to embodiment 2. Barrel unit 202 includes a barrel 217 that houses, for example, multiple lenses, a first lens 211, a second lens 212, a third lens 213, a fourth lens 214, and a fifth lens 215 from the subject side. In addition, barrel 217 has a spacer 216 that is disposed between the third lens 213 and the fourth lens 214.

[0046] Furthermore, it has a pressing member 218a that contacts first lens 211 to hold the lens on barrel 217, a biased member 219a as a biased portion, and an elastic member 220. In this embodiment, first lens 211, second lens 212, third lens 213, fourth lens 214, and fifth lens 215 are glass lenses. Moreover, spacer 216, barrel 217, and pressing member 218a are made of metal, and biased member 219a is made of a resin material.

[0047] The number of lenses, the number of spacers, and the materials of the lenses, spacers, and lens barrel can be set as desired depending on the application. Such lens barrel unit 202 may be provided with an "aperture diaphragm" that limits the amount of transmitted light and determines the F-number, which is an index of brightness, or a "light blocking diaphragm" that blocks light rays that cause ghosts and light rays that cause aberrations. However, this is omitted in this embodiment.

[0048] Elastic member 220 is made of a rubber material such as silicone rubber that takes into consideration heat resistance so that its physical properties are not affected even in a severe vehicle temperature environment, or a metal spring such as a compression coil spring or a wave washer. Elastic member 220 is sandwiched and held in the optical axis O direction by lens barrel 217 and biased member 219a fixed to pressing member 218a.

[0049] Here, we will explain how to assemble the lens barrel unit 202. In the lens barrel unit 202, the first lens 211, the second lens 212, the third lens 213, the fourth lens 214, the fifth lens 215, and the spacer 216 are housed inside the lens barrel 217. Next, in this state, the pressing member 218a is brought into contact with the first lens 211 from the subject side, and the lens barrel mating portion 217a and the pressing member mating portion 218b are mated and inserted.

[0050] On the other hand, elastic member 220 and urged member 219a are inserted from the side opposite the subject side, and pressing member 218a and urged member 219a are fixed in a state in which elastic member 220 is compressed. This makes it possible to fix the lens to barrel 217 in the optical axis O direction.

[0051] With elastic member 220 compressed to the required amount, first lens 211 is held by pressing member 218a and biased member 219a, so that first lens 211 is constantly pressed against pressing member 218a by the reaction force due to the elastic force of elastic member 220.

[0052] The urged member 219a is fixed by, for example, press-fitting the outer diameter of the urged member 219a into the inner diameter of the pressing member 218a. At this time, the pressing member 218a and the urged member 219a may be fixed with an adhesive 221.

[0053] As a result, pressing member 218a and biased member 219a are integrated and can receive the reaction force due to the elastic force of elastic member 220 that is compressed during assembly. Adhesive 221 may be a UV-curable adhesive, a thermosetting adhesive, an anaerobic adhesive, or the like.

[0054] 5 is a cross-sectional view of barrel unit 202 in the case where a biased member is screwed and fixed to a pressing member according to embodiment 2. Pressing member 218c has a female screw portion on its inner diameter portion, and biased member 219b as a biased portion is provided with a male screw portion on its outer diameter portion. By screwing the female screw portion of pressing member 218c and the male screw portion of biased member 219b, pressing member 218c and biased member 219b can be fixed in a state where elastic member 220 is compressed by a required amount.

[0055] The pressing member 218c and the urged member 219b may be provided with a pressing member groove 218e and a urged member groove 219c, respectively, whose depth direction has a component in the optical axis direction. The pressing member groove 218e and the urged member groove 219c function as rotation restricting portions when the pressing member 218c and the urged member 219b are screwed together, and can suppress co-rotation of the pressing member 218c and the urged member 219b during assembly.

[0056] The shape of the urged member groove 219c is not limited to this. It is sufficient that the urged member 219b has a recess or protrusion on the image surface side whose depth direction has a component in the optical axis direction. The pressing member groove 218e is also not limited to this shape. It is sufficient that the pressing member 218c has a recess or protrusion on the subject side whose depth direction has a component in the optical axis direction.

[0057] It is also possible to prevent misalignment after assembly by applying a thread locking agent to the male thread portion of the urged member 219b and screwing it into the female thread portion of the pressing member 218c.

[0058] As described above, an optical system having a wide viewing angle is characterized in that, among multiple lenses, first lens 211, which is closest to the subject, has a larger outer diameter size than the other lenses. However, elastic member 220 is disposed on the image plane side (opposite the subject side) of first lens 211 via lens barrel 217. Therefore, pressing members 218a and 218c can press first lens 211 without increasing the outermost diameter of lens barrel unit 202 including pressing members 218a and 218c.

[0059] Furthermore, even if elastic member 220 is twisted during assembly or compressed in a direction perpendicular to the optical axis O, it remains engaged at lens barrel engagement portion 217a and presser member engagement portions 218b and 218d. Therefore, elastic member 220 can press the lens in the direction of optical axis O without exceeding the engagement play between lens barrel engagement portion 217a and presser member engagement portions 218b and 218d.

[0060] Moreover, pressing members 218a and 218c constantly press first lens 211 with a reaction force of the elastic force of elastic member 220. Therefore, when the environmental temperature becomes low after assembly, lens deformation caused by fastening due to the difference in linear expansion coefficient between lens barrel 217 and the lens can be absorbed by elastic member 220.

[0061] In this embodiment, the lens barrel 217, the pressing member 218c, and the spacer 216 are made of an aluminum alloy, and have a linear expansion coefficient of 26×10^-6 / °C. The first lens 211, the second lens 212, the third lens 213, the fourth lens 214, and the fifth lens 215 are made of glass, and have a linear expansion coefficient of 7×10^-6 / °C.

[0062] The length of spacer 216 in the optical axis direction is 1.5 mm, and the length in the optical axis direction from wall 217b of barrel 217 to the contact part of pressing member 218c with first lens 211 is 10 mm. The optical axis thickness of second lens 212, third lens 213, fourth lens 214, and fifth lens 215 is 1 mm. In this case, a 1°C change in temperature causes a difference in the gap between the barrel and the lenses of 0.16 μm.

[0063] Therefore, in an environment where the outside air temperature drops by 60° C. from the time of assembly, the lens will deform by 9.7 μm in the optical axis direction, but the elastic member 220 can absorb this deformation.

[0064] On the other hand, in an environment where the outside air temperature rises by 60° C. from the time of assembly, a backlash of 9.7 μm will occur in the optical axis direction. However, by assembling the lens in a state where elastic member 220 is compressed by the required amount, pressing member 218c constantly presses and holds first lens 211 with the reaction force of the elastic force of elastic member 220, so that this backlash can be absorbed.

[0065] 5, the urged member 219b fixed to the pressing member 218c is assembled in a state in which the elastic member 220 is compressed until it comes into contact with the lens barrel 217. This makes it possible to apply a constant elastic force to the elastic member 220 without being affected by the machining dimensional tolerance of the lens and spacer in the optical axis O direction component.

[0066] The compression amount of elastic member 220 is set so as to absorb the amount of tightening and backlash that occurs when temperature changes. This provides elastic force to elastic member 220, enabling constant and stable pressing against first lens 211 by pressing member 218c. In addition, the inner diameter position of elastic member 220 is determined by the outer diameter of lens barrel 217. This guides the radial position of elastic member 220, improving assembly stability.

[0067] In this embodiment, elastic member 220 is disposed on the image plane side of first lens 211 via lens barrel 217. Therefore, the elements that determine the radial size of lens barrel unit 202 are only the thicknesses of first lens 211 and lens barrel 217 and pressing member 218c. This makes it possible to hold the lens without increasing the size even in an optical system with a wide viewing angle.

[0068] This makes it possible to reduce the installation space required for the optical device 101 on the vehicle body, where a portion of the outer diameter of the lens barrel of the lens barrel unit 202 is exposed. In addition, by making the optical device 101 smaller, it becomes possible to install an anti-glare hood (not shown) that extends from below the optical device 101 toward the windshield 106 without increasing its size.

[0069] According to the above embodiment, by arranging an elastic member in the gap created by the diameter difference between the lens on the subject side and the subsequent lens, which is the largest characteristic of a wide-angle camera, it is possible to prevent the diameter of the lens barrel unit on the subject side from becoming large. Also, by compressing the elastic member in advance by the required amount and giving it elasticity, the pressing member is always pressed against the lens, making it possible to absorb rattle and tightening caused by temperature changes.

[0070] <Embodiment 3> In the first and second embodiments, an example of a configuration in which a pressing member presses the lens on the subject side, and a biased portion presses the lens barrel via an elastic body on the image surface side has been described. However, in the third embodiment, an example will be described in which a pressing member presses a part of the lens on the image surface side, and elastically presses a part of another lens on the subject side.

[0071] In addition, in the case of a configuration in which the elastic member is sandwiched and held between the presser ring and the lens, the rotation of the presser ring may cause the elastic member to become twisted. If the elastic member is held in a twisted state, an even force is not applied from the presser ring to the lens via the elastic member, which may deteriorate the lens holding accuracy and induce deterioration of the optical performance.

[0072] Therefore, in the third embodiment as well, the twisting deformation of the elastic member is suppressed, a uniform force can be applied to the lens, and the diameter of the lens barrel unit on the subject side can be made smaller. To this end, at least one lens, a lens barrel that houses the lens, and a presser ring that holds the lens are provided, the lens barrel has a wall portion on the subject side of the lens, and includes an elastic member that is sandwiched between the wall portion and the first lens that is disposed closest to the subject side of the lens.

[0073] The first lens is held apart from the wall, and the presser ring is screwed into the outer diameter part of the lens barrel on the opposite side of the optical axis from the wall and the first lens, and is held by being butted against a predetermined contact surface that comes into contact in the optical axis direction. The contact surface is provided on the lens barrel.

[0074] In embodiment 3, the elastic member is held by being sandwiched between a wall portion provided on the subject side of the lens barrel and the first lens positioned closest to the subject, so that the elastic member can apply an even force to hold the lens without deformation such as twisting due to rotation of the pressure ring.

[0075] In addition, by arranging the presser ring on the side opposite the wall portion in the optical axis direction with respect to the first lens, the factors that determine the diameter of the lens barrel unit on the subject side are the lens diameter and the lens barrel thickness, making it possible to reduce the diameter of the lens barrel unit. This makes it possible to reduce the installation space on the vehicle body. Below, the third embodiment will be described in detail.

[0076] 6 is a cross-sectional view illustrating the structure of barrel unit 302 according to embodiment 3. Barrel unit 302 has a barrel 311 that houses elastic member 312, first lens 313 arranged closest to the subject, lens 316a, lens 316b, and spacer 314a and spacer 314b that are sandwiched between the lenses. Furthermore, barrel unit 302 has a retainer ring 315 that is screwed into barrel 311 and holds lens 316b.

[0077] Lens barrel 311, spacer 314a, spacer 314b and retainer ring 315 are made of a metal material or a resin material, while first lens 313, lenses 316a and 316b are made of a transparent material such as glass or a resin material. Lens barrel 311 has wall 317 and male screw portion 311a on the outer diameter portion. Wall 317 is provided on the subject side of first lens 313, which is arranged closest to the subject, and has a surface with which elastic member 312 comes into contact.

[0078] For example, in the case of a lens barrel for a camera having a function of capturing an image of the area ahead of the vehicle and tracking a preceding vehicle, it is necessary to narrow the viewing angle and capture distant objects in order to improve the functionality when driving on a highway, etc. However, as in this embodiment, even if the wall portion 317 is provided, the effective light rays are not blocked and the camera function of capturing distant objects can be fully achieved.

[0079] Elastic member 312 is made of a rubber material such as silicone rubber that takes into consideration heat resistance so that its physical properties are not affected even in the harsh temperature environment in a vehicle, and is held by being sandwiched between first lens 313 and wall portion 317.

[0080] The press ring 315 has a female screw portion 315a, and is disposed on the opposite side in the optical axis direction (image surface side) to the wall portion 317 with respect to the first lens 313. The press ring 315 is screwed (fastened) to the male screw portion 311a until it abuts against a contact surface 318 while contacting the peripheral portion of the lens 316b disposed closest to the image surface.

[0081] In this embodiment, contact surface 318 is provided on lens barrel 311. This determines the positions of first lens 313, spacer 314a, lens 316a, spacer 314b, and lens 316b in the optical axis direction. At this time, elastic member 312 is sandwiched between wall portion 317 by the pressure of first lens 313 due to screwing of retaining ring 315, and is deformed, but the elastic force of elastic member 312 is absorbed.

[0082] In this embodiment, the presser ring 315 is screwed to the male thread portion 311a and the female thread portion 315a on the outer diameter portion of the lens barrel 311. Therefore, compared to the case where the presser ring 315 is screwed to the inner diameter portion of the lens barrel 311, the distance between the R2 surface of the lens 316b on the optical axis and the image sensor included in the electrical device 104 can be made shorter. This allows the length of the lens barrel unit 302 in the optical axis direction to be reduced, and the effects of curvature of field aberration and the like to be reduced, improving the optical performance.

[0083] During assembly, the rotation caused by screwing the retainer ring 315 is not transmitted to the elastic member 312 because it goes through the lens and spacer, and the elastic member 312 is pressed with an even force from the first lens 313, so that the elastic member 312 can be held without being twisted or deformed. This makes it possible to prevent deterioration in the accuracy of holding the lens by the elastic member.

[0084] Furthermore, by holding the first lens 313 apart from the wall portion 317, when the environmental temperature drops from the time of assembly, the deformation of the lens caused by tightening due to the difference in linear expansion coefficient between the lens barrel 311 and the lens can be absorbed by the elastic member 312.

[0085] In this embodiment, the lens barrel 311, the presser ring 315, the spacer 314a, and the spacer 314b are made of an aluminum alloy and have a linear expansion coefficient of 26×10^-6 / ° C. The first lens 313, the lens 316a, and the lens 316b are made of glass and have a linear expansion coefficient of 7×10^-6 / ° C.

[0086] The lengths of spacer 314a and spacer 314b in the optical axis direction are 2 mm and 9 mm, respectively, and the distance in the optical axis direction from wall 317 of lens barrel 311 to the contact portion of presser ring 315 with lens 316b is 19 mm. For the sake of simplicity of calculation, elastic member 312 is excluded from the calculation because it is easily deformed. In this case, a temperature change of 1°C causes a difference in the distance between the lens barrel and the lens of 0.16 μm.

[0087] Therefore, in an environment where the outside air temperature drops by 60°C from the time of assembly, a lens deformation of 9.6 μm will occur in the optical axis direction. However, because first lens 313 and wall portion 317 are held apart, this deformation amount can be absorbed by elastic member 312.

[0088] Furthermore, in an environment where the outside air temperature rises by 60°C from the time of assembly, a backlash of 9.6 μm will occur in the optical axis direction. However, during assembly, first lens 313 is pressed by fastening press ring 315 with the screws, and is sandwiched between wall portion 317, and elastic member 312 is held in an elastic state, so this amount of backlash can be absorbed.

[0089] Furthermore, the pressure applied to first lens 313 by tightening the screws of retaining ring 315 brings wall 317 and elastic member 312, and also elastic member 312 and first lens 313, into tight contact. This improves the sealing performance of lens barrel unit 302, making it possible to obtain waterproof and moisture-proof properties. Elastic member 312 has an annular shape in this embodiment, and by providing wall 317 of lens barrel 311 with an annular groove (groove shape) capable of accommodating the elastic member, it is possible to suppress positional displacement of elastic member 312 in the direction perpendicular to the optical axis and deformation in the outer circumferential direction.

[0090] In this embodiment, by arranging the pressure ring 315 on the opposite side of the optical axis direction (image surface side) from the wall portion 317 of the lens barrel 311 and the first lens 313, the factors that determine the radial size of the lens barrel unit 302 on the subject side can be the only factors outer diameter of the lens and thickness of the lens barrel.

[0091] 1, when the lens barrel 311 of the lens barrel unit 302 is exposed from the housing 103, the radial size of the lens barrel unit 302 can be made smaller than when the presser ring 315 is disposed on the subject side. Therefore, the optical device 101 can be installed closer to the windshield 106, and the installation space for the optical device 101 relative to the vehicle body can be reduced.

[0092] As described above, in this embodiment, the wall portion 317 of the lens barrel 311 is provided on the subject side, and the elastic member 312 is held between the first lens 313 arranged closest to the subject and the wall portion 317. Therefore, there is no effect from the rotation of the pressing ring 315, and the elastic member 312 is held without being twisted or deformed.

[0093] This makes it possible to suppress deterioration of lens holding accuracy during assembly when loosening in the optical axis direction due to changes in environmental temperature and when tightening is relaxed using an elastic member. Also, by arranging presser ring 315 on the subject side and on the opposite side in the optical axis direction to first lens 313, it becomes possible to reduce the radial size of lens barrel unit 302 on the subject side, and the installation space for optical device 101 on the vehicle body can be reduced.

[0094] <Embodiment 4> In the third embodiment, an example of a configuration in which one pressing ring is provided on the lens barrel is described, but in the fourth embodiment, a lens barrel in which two or more pressing rings are provided on the lens barrel is described.

[0095] 7 is a cross-sectional view illustrating the structure of barrel unit 303 according to embodiment 4. Barrel unit 303 has barrel 321 that houses elastic member 322, first lens 323 arranged closest to the subject, lenses 326a, 326b, and 326c, and spacer 324 sandwiched between first lens 323 and lens 326a. Furthermore, barrel unit 303 has retainer ring 325 and retainer ring 329 that screw into barrel 321.

[0096] Lens barrel 321, spacer 324, retainer ring 325, and retainer ring 329 are made of a metal material or a resin material, while first lens 323, lens 326a, lens 326b, and lens 326c are made of a transparent material such as glass or a resin material.

[0097] Lens barrel 321 has wall 327, male thread 321a on its outer diameter, and female thread 321b on its inner diameter. Wall 327 is provided on the subject side of first lens 323, and has a surface with which elastic member 322 comes into contact.

[0098] Elastic member 322 is made of a rubber material such as silicone rubber that takes into consideration heat resistance so that its physical properties are not affected even in the harsh temperature environment in a vehicle, and is held by being sandwiched between first lens 323 and wall portion 327.

[0099] The retaining ring 325 has a male thread portion 325a and is arranged on the opposite side (image surface side) of the wall portion 327 with respect to the first lens 323, and is screwed (fastened) to the female thread portion 321b until it abuts against the contact surface 328 while contacting the peripheral portion of the lens 326b that is arranged closest to the image surface.

[0100] In this embodiment, contact surface 328 is provided on lens barrel 321. This determines the positions in the optical axis direction of first lens 323, spacer 324, lens 326a, and lens 326b. At this time, elastic member 322 is sandwiched between wall portion 327 by the pressure of first lens 323 due to screwing of retaining ring 325, and is deformed, but the elastic force of elastic member 322 is absorbed.

[0101] The rotation caused by screwing the presser ring 325 is not transmitted to the elastic member 322 because it goes through the lens and spacer, and the elastic member 322 can be held without being twisted or deformed because it is pressed with an even force from the first lens 323. This makes it possible to suppress deterioration in the accuracy of holding the lens by the elastic member.

[0102] Lens 326c comes into contact with press ring 325, the position of which in the optical axis direction is determined by hitting contact surface 328, and is housed in lens barrel 321. Furthermore, female thread portion 329a of press ring 329 is screwed (fastened) to male thread portion 321a of lens barrel 321, so that lens 326c is held in a state where its position in the optical axis direction is determined.

[0103] Furthermore, by holding the first lens 323 apart from the wall portion 327, when the environmental temperature drops from the time of assembly, the lens deformation caused by tightening due to the difference in linear expansion coefficient between the lens barrel 321 and the lens can be absorbed by the elastic member 322.

[0104] Here, we will explain the components of first lens 323, lens 326a, and lens 326b, which are particularly susceptible to significant looseness and tightening when the environmental temperature changes. Lens barrel 321, presser ring 325, and spacer 324 are made of aluminum alloy and have a linear expansion coefficient of 26×10^-6 / ℃.

[0105] First lens 323, lens 326a, and lens 326b are made of glass, and have a linear expansion coefficient of 7×10^-6 / ℃. The length of spacer 324 in the optical axis direction is 2 mm, and the distance in the optical axis direction from wall 327 of lens barrel 321 to the contact part of press ring 325 with lens 326b is 13 mm. For the sake of simplicity of calculation, elastic member 322 is excluded from the calculation because it is easily deformed. In this case, a 1℃ change in temperature causes a difference in the distance between the lens barrel and the lens of 0.22 μm.

[0106] Therefore, in an environment where the outside air temperature drops by 60°C from the time of assembly, a lens deformation of 13.2 μm will occur in the optical axis direction. However, because first lens 323 and wall portion 327 are kept apart, this deformation amount can be absorbed by elastic member 322.

[0107] Furthermore, in an environment where the outside air temperature rises by 60°C from the time of assembly, a backlash of 13.2 μm will occur in the optical axis direction. However, since first lens 323 is pressed by screwing press ring 325 during assembly, and is sandwiched between wall portion 327, and elastic member 322 is held in an elastic state, this backlash can be absorbed.

[0108] In this embodiment, pressing ring 325 and pressing ring 329 are disposed on the opposite side in the optical axis direction (image surface side) to wall portion 327 with respect to first lens 323 of barrel 321. Therefore, the factors that determine the radial size of barrel unit 303 on the subject side can be the only lens outer diameter and barrel thickness.

[0109] In other words, since the radial size of lens barrel unit 303 can be made smaller than when the presser ring is located on the subject side, the optical device including lens barrel unit 303 can be installed closer to the windshield of the vehicle, thereby reducing the installation space required for the vehicle body.

[0110] Furthermore, by providing a wall 327 of the lens barrel 321 on the subject side and holding the elastic member 322 between the wall 327 and the first lens 323 arranged closest to the subject, the elastic member 322 is held without being twisted or deformed, without being affected by the rotation of the pressing ring 325. This makes it possible to suppress deterioration of the lens holding accuracy during assembly when using an elastic member to ease backlash in the optical axis direction due to changes in environmental temperature and to reduce tightening.

[0111] In addition, by disposing presser ring 329 on the opposite side of wall portion 327 in the optical axis direction with respect to first lens 323, it is possible to reduce the radial size of lens barrel unit 303 on the subject side. Therefore, the installation space of the optical device including lens barrel unit 303 on the vehicle body can be reduced.

[0112] <Embodiment 5> In the third and fourth embodiments, examples of a configuration in which the pressing ring is directly abutted against the lens barrel have been described, but in the fifth embodiment, an example of a configuration in which the pressing ring contacts the lens barrel via a ring member will be described.

[0113] 8 is a cross-sectional view illustrating the structure of barrel unit 304 according to embodiment 5. Barrel unit 304 has barrel 331 that houses elastic member 332, first lens 333 arranged closest to the subject, lens 336a, lens 336b, and spacer 334a and spacer 334b ​​that are sandwiched between the lenses. Barrel unit 304 also has retainer ring 335 that screws into barrel 331.

[0114] The lens barrel 331, the spacer 334a, the spacer 334b, and the retainer ring 335 are made of a metal material or a resin material, while the first lens 333, the lens 336a, and the lens 336b are made of a transparent material such as glass or a resin material.

[0115] Lens barrel 331 has wall portion 337 and male screw portion 331a on its outer diameter portion. Wall portion 337 is provided on the subject side of first lens 333, and has a surface with which elastic member 332 comes into contact. Elastic member 332 is made of a rubber material such as silicone rubber that takes into consideration heat resistance so that its physical properties are not affected even in a harsh in-vehicle temperature environment, and is held by being sandwiched between first lens 333 and wall portion 337.

[0116] In this embodiment, a ring member 339 is provided which is sandwiched between the lens barrel 331 and the pressing ring 335. The pressing ring 335 has a female thread portion 335a, is disposed on the opposite side of the wall portion 337 with respect to the first lens 333, and is screwed (fastened) to the male thread portion 331a of the lens barrel 331 until it abuts against a contact surface 338 while contacting the lens 336b.

[0117] In this embodiment, the contact surface 338 is provided on a ring member 339. The ring member 339 is made of a metal material or a resin material. This determines the positions of the first lens 333, the spacer 334a, the lens 336a, the spacer 334b, and the lens 336b in the optical axis direction. At this time, the elastic member 332 is sandwiched between the wall portion 337 by the pressure of the first lens 333 due to the screw tightening of the retaining ring 335, and is deformed, but the elastic force of the elastic member 332 is absorbed.

[0118] Moreover, by arranging the presser ring 335 on the side opposite to the wall portion 337 in the optical axis direction with respect to the first lens 333, it is possible to reduce the radial size of the lens barrel unit 304 on the subject side. Therefore, it is possible to bring the optical device including the lens barrel unit 304 closer to the inclined windshield, and the installation space on the vehicle body can be reduced.

[0119] Dimensional tolerances arise during the manufacturing process of each part that constitutes the lens barrel unit 304. In other words, the lens barrel unit 304 is designed to give an appropriate elastic force to the elastic member 332, taking into consideration the dimensional tolerance of the wire diameter of the elastic member 332, and the dimensional tolerance of the lenses, spacers, and lens barrel in the optical axis direction.

[0120] However, depending on the above-mentioned dimensional tolerances and the wire diameter and hardness of the elastic member 332, the elastic force may become excessive, which may induce lens deformation or cracking.

[0121] In contrast, in this embodiment, a ring member 339 is provided between the lens barrel 331 and the pressing ring 335, and a contact surface 338 is provided on the ring member 339. By increasing the thickness of the ring member 339 in the optical axis direction, the distance between the R1 surface of the first lens 333 and the contact surface of the pressing ring 335 with the lens 336b increases, and the elastic force of the elastic member 332 can be reduced. This makes it possible to suppress deterioration in the lens holding accuracy caused by the elastic member.

[0122] Furthermore, a wall portion 337 of the lens barrel 331 is provided on the subject side, and the elastic member 332 is held between the wall portion 337 and the first lens 333 arranged closest to the subject, so that the elastic member 332 is held without being twisted or deformed without being affected by the rotation of the pressing ring 335.

[0123] Furthermore, by providing a ring member 339 between the lens barrel 331 and the pressing ring 335 and providing the ring member 339 on the contact surface 338, it is possible to prevent the elastic member 332 from having excessive elastic force due to the dimensional tolerances of each part and the material and hardness of the elastic member 332. Therefore, it is possible to prevent deterioration of the lens holding accuracy during assembly when using an elastic member to alleviate backlash in the optical axis direction due to changes in environmental temperature and tightening.

[0124] Moreover, by disposing presser ring 335 on the opposite side of wall portion 337 in the optical axis direction with respect to first lens 333, it is possible to reduce the radial size of lens barrel unit 304 on the subject side. Therefore, it is possible to reduce the installation space of the optical device including lens barrel unit 304 on the vehicle body.

[0125] In the above embodiment, the number of lenses in the lens barrel unit may be any number of lenses as long as it is one or more. In addition, the lens barrel unit is applied to an in-vehicle camera used for driving assistance or automatic driving, but may be applied to optical devices other than the in-vehicle camera. In addition, the lens barrel unit in the above embodiment is not only suitable for an in-vehicle camera for capturing an image of the front of a vehicle, but can also be applied to an in-vehicle camera for capturing an image of the rear or side of a vehicle.

[0126] <Embodiment 6> 9 is a schematic diagram of an imaging device according to embodiment 6. An imaging device 90 as an optical device 101 according to this embodiment includes the barrel unit 102 of the above-described embodiment, a light receiving element 92 that photoelectrically converts an image of an object formed by an optical system 201 in the barrel unit 102, and a housing 103 that holds the light receiving element 92. That is, the imaging device includes a lens device and an imaging element that images an object via the lens device.

[0127] The lens barrel unit 102 is held by a lens barrel (holding member) and connected to a housing 103. As shown in Fig. 9, a display unit 94 that displays an image acquired by the light receiving element 92 may be connected to the housing 103. As the light receiving element 92, an imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor can be used.

[0128] When the imaging device 90 is used as a distance measuring device, for example, an imaging element (image plane phase difference sensor) having pixels capable of splitting a light beam from an object into two and photoelectrically converting the split light beam can be used as the light receiving element 92. When the subject is on the focal plane of the optical system 201, no positional shift occurs between the images corresponding to the two split light beams on the image plane of the optical system 201.

[0129] However, when the subject is located at a position other than the focal plane of the optical system 201, a positional shift occurs in each image. In this case, the positional shift of each image corresponds to the amount of displacement from the focal plane of the subject, so the distance to the subject can be measured by acquiring the amount and direction of the positional shift of each image using an imaging surface phase difference sensor.

[0130] The lens barrel unit 102 and the housing 103 may be configured to be detachable from each other. That is, the lens barrel unit 102 and the lens barrel may be configured as an interchangeable lens (lens device). The lens barrel unit 102 and the optical system 201 according to the above-mentioned embodiment may be applied to imaging devices such as digital still cameras, silver halide film cameras, video cameras, vehicle-mounted cameras, and surveillance cameras. Furthermore, the lens barrel unit 102 and the optical system 201 may be applied to various optical devices such as telescopes, binoculars, projectors (projection devices), and digital copiers.

[0131] 10(A) and (B) are schematic diagrams of a moving device according to embodiment 6 and diagrams showing optical characteristics of the optical system. Fig. 10(A) is a schematic diagram of a moving device 100 according to an embodiment of the present invention and an imaging device 1102 as an on-board camera mounted thereon. Fig. 10(A) shows a case where the moving device 100 is an automobile (vehicle). The moving device 100 is capable of moving while holding the imaging device.

[0132] The mobile device 100 is equipped with an in-vehicle system (driving assistance device) (not shown) for assisting a user 140 (driver, passenger, etc.) of the mobile device 100 using images captured by the imaging device 1102.

[0133] In this embodiment, the imaging device 1102 is installed so as to capture an image of the rear of the mobile device 100, but as described in Fig. 1, the imaging device 1102 may be installed so as to capture an image of the front of the mobile device 100. In addition, two or more imaging devices 1102 may be installed in two or more locations on the mobile device 100.

[0134] The imaging device 1102 includes an optical system 201 according to any one of the above-described embodiments and an imaging unit 210. In this embodiment, the optical system 201 is an optical system (different angle of view lens) having different imaging magnifications at a first angle of view (first field of view) 130 and a second angle of view (second field of view) 131 that is larger than the first angle of view 130 and is located outside the first angle of view.

[0135] The imaging surface (light receiving surface) of the imaging unit 210 includes a first region for imaging an object included in a first angle of view 130, and a second region for imaging an object included in a second angle of view 131 outside the first region. In this case, the number of pixels per unit angle of view in the first region is greater than the number of pixels per unit angle of view in the second region excluding the first region. In other words, the resolution of the imaging device 1102 in the first angle of view (first region) is higher than the resolution in the second angle of view (second region).

[0136] The optical characteristics of the optical system 201 will be described in detail below. The left diagram in Fig. 10(B) shows, in contour lines, the image height y [mm] at each half angle of view θ [deg.] on the imaging surface of the imaging unit 210. The right diagram in Fig. 10(B) shows, in a graph, the relationship between each half angle of view θ and the image height y in the first quadrant of the left diagram (projection characteristics of the optical system 201).

[0137] As shown in Fig. 10B, the optical system 201 is configured such that the projection characteristic y(θ) differs between angles of view less than a predetermined half angle of view θa and angles of view equal to or greater than the half angle of view θa. Therefore, the increase in image height y (resolution) per unit half angle of view θ also differs for each angle of view. The local resolution of the optical system 201 is expressed as the differential value dy(θ) / dθ of the projection characteristic y(θ) with respect to the half angle of view θ.

[0138] In the left diagram of Fig. 10(B), the resolution is higher as the interval between the contour lines of the image height y for each half angle of view θ increases, while in the right diagram of Fig. 10(B), the resolution is higher as the slope of the graph of the projection characteristic y(θ) increases.

[0139] In the left diagram of Fig. 10(B), the first region 201a, which is the central region, corresponds to an angle of view less than the half angle of view θa, and the second region 201b, which is the peripheral region, corresponds to an angle of view equal to or greater than the half angle of view θa. The angle of view less than the half angle of view θa corresponds to the first angle of view 130 in Fig. 10(A), and the combined angle of view less than the half angle of view θa and the angle of view equal to or greater than the half angle of view θa corresponds to the second angle of view 131 in Fig. 10(A).

[0140] As described above, the first region 201a is a region with high resolution and low distortion, and the second region 201b is a region with low resolution and high distortion. Note that the ratio θa / θmax of the half angle of view θa to the maximum half angle of view θmax is preferably 0.15 to 0.35, and more preferably 0.16 to 0.25.

[0141] For example, in the above embodiment, since the maximum half angle of view θmax=90°, the value of the half angle of view θa is preferably 13.5° or more and 31.5° or less, and more preferably 14.4° or more and 22.5° or less.

[0142] The optical system 201 is configured such that the projection characteristic y(θ) in the first region 201a is different from f×θ (equidistant projection method) and is also different from the projection characteristic in the second region 201b. In this case, it is desirable that the projection characteristic y(θ) of the optical system 201 satisfies the following conditional expression (1). 1.0 <f×sin(θmax) / y(θmax)≦1.9 (1)

[0143] By satisfying conditional expression (1), it is possible to realize a wider angle of view of the optical system 201 by reducing the resolution in the second region 201b. Furthermore, it is possible to achieve a higher resolution in the first region 201a than in the central region of a general fisheye lens that employs the orthogonal projection method (y(θ)=f×sinθ).

[0144] If the lower limit of conditional formula (1) is exceeded, the resolution in the first region 201a will be lower than that of an orthogonal projection type fisheye lens, or the maximum image height will be larger, leading to an increase in the size of the optical system, which is undesirable. On the other hand, if the upper limit of conditional formula (1) is exceeded, the resolution in the first region 201a will be too high, making it difficult to achieve a wide angle of view equivalent to that of an orthogonal projection type fisheye lens, or making it impossible to maintain good optical performance, which is undesirable.

[0145] Furthermore, it is preferable that the following conditional expression (2) be satisfied, and it is even more preferable that the following conditional expression (3) be satisfied. 1.0 <f×sin(θmax) / y(θmax)≦1.7 (2) 1.0 <f×sin(θmax) / y(θmax)≦1.4 (3)

[0146] As described above, in the first region 201a, the distortion of the optical system 201 is small and the resolution is high, so that a high-definition image can be obtained compared to the second region 201b. Therefore, by setting the first region 201a (first angle of view 130) to be the attention region of the user 140, good visibility can be obtained.

[0147] For example, when the imaging device 1102 is disposed at the rear of the mobile device 100 as shown in Fig. 10(A), a natural sense of perspective can be obtained when the user 140 gazes at a rear vehicle or the like by displaying an image corresponding to the first angle of view 130 on the electronic rearview mirror. On the other hand, the second area 201b (second angle of view 131) corresponds to a wide angle of view including the first angle of view 130. Therefore, for example, when the mobile device 100 is backing up, driving assistance can be provided to the user 140 by displaying an image corresponding to the second angle of view 131 on an in-vehicle display.

[0148] 11 is a functional block diagram showing a configuration example of an in-vehicle system according to embodiment 6. An in-vehicle system 1101 in embodiment 6 illustrates a system for displaying to a user 140 an image obtained by an imaging device 1102 installed behind a moving device 100. The in-vehicle system 1101 has the imaging device 1102, a processing device 1120, and a display device (display unit) 1130 that displays an image obtained based on the output of the imaging device. The imaging device 1102 has the optical system 201 and the imaging unit 210 as described above.

[0149] The imaging unit 210 includes an imaging element such as a CCD sensor or a CMOS sensor, and performs photoelectric conversion on an optical image formed by the optical system 201 to generate imaging data, which is then output to the processing device 1120 .

[0150] The processing device 1120 includes an image processing unit 1121, a display angle of view changing unit 1122, a rear vehicle distance detection unit 1123, a display angle of view determination unit 1124, a reverse gear detection unit 1125, a user setting changing unit 1126, and the like.

[0151] The processing device 1120 is a computer such as a CPU (Central Processing Unit) microcomputer, and functions as a control unit that controls the operation of each component based on a computer program.

[0152] At least one of the components in the processing device 1120 may be realized by hardware such as an application specific integrated circuit (ASIC) or a programmable logic array (PLA).

[0153] The image processing unit 1121 generates image data by performing image processing such as WDR (Wide Dynamic Range) correction, gamma correction, LUT (Look Up Table) processing, and distortion correction on the imaging data acquired from the imaging unit 210. Note that the distortion correction is performed on at least the imaging data corresponding to the second region 201b.

[0154] This makes it easier for the user 140 to view the image displayed on the display device 1130, and improves the detection rate of the rear vehicle in the rear vehicle distance detection unit 1123. It is not necessary to perform distortion correction on the captured image data corresponding to the first area 201a. The image processing unit 1121 outputs the image data generated by executing the image processing as described above to the display angle changing unit 1122 and the rear vehicle distance detection unit 1123.

[0155] The rear vehicle distance detection unit 1123 uses image data output from the image processing unit 1121 to obtain information regarding the distance to the rear vehicle contained in image data corresponding to the range of the second angle of view 131 that does not include the first angle of view 130.

[0156] For example, the rear vehicle distance detection unit 1123 can detect a rear vehicle based on image data corresponding to the second region 201b among the image data, and calculate the distance to the vehicle from the change in position or size of the detected rear vehicle. The rear vehicle distance detection unit 1123 outputs information on the calculated distance to the display angle of view determination unit 1124.

[0157] Furthermore, the rear vehicle distance detection unit 1123 may determine the type of vehicle behind based on data regarding characteristic information such as shape and color for each vehicle type, which is output as a result of machine learning (deep learning) based on images of a large number of vehicles.

[0158] At this time, the rear vehicle distance detection unit 1123 may output information regarding the vehicle type of the rear vehicle to the display view angle determination unit 1124. The reverse gear detection unit 1125 detects whether the transmission of the moving device 100 (host vehicle) is in reverse gear, and outputs the detection result to the display view angle determination unit 1124.

[0159] The display angle of view determination unit 1124 determines whether the angle of view (display angle of view) of the image to be displayed on the display device 1130 should be the first angle of view 130 or the second angle of view 131, based on the output from at least one of the rear vehicle distance detection unit 1123 or the reverse gear detection unit 1125.

[0160] Then, depending on the determination result, the display angle of view determination unit 1124 outputs to the display angle of view change unit 1122. For example, the display angle of view determination unit 1124 can determine that the display angle of view should be the second angle of view 131 when the distance value in the distance information is equal to or smaller than a certain threshold value (e.g., 3 m), and can determine that the display angle of view should be the first angle of view 130 when the distance value is greater than the threshold value.

[0161] Alternatively, when the reverse gear detection unit 1125 notifies the display angle of view determination unit 1124 that the transmission of the mobile device 100 is in reverse gear, the display angle of view determination unit 1124 determines to set the display angle of view to the second angle of view 131. Moreover, when the mobile device 100 is not in reverse gear, the display angle of view determination unit 1124 determines to set the display angle of view to the first angle of view 130.

[0162] Furthermore, when the transmission of the mobile device 100 is in reverse gear, the display angle of view determination unit 1124 can determine that the display angle of view should be the second angle of view 131 regardless of the result of the rear vehicle distance detection unit 1123. Also, when the transmission of the mobile device 100 is not in reverse gear, the display angle of view determination unit 1124 can determine that the display angle of view should be determined according to the detection result of the rear vehicle distance detection unit 1123.

[0163] The display angle of view determination unit 1124 may change the determination criterion for changing the angle of view according to the vehicle type of the mobile device 100 by receiving vehicle type information from the rear vehicle distance detection unit 1123. For example, when the mobile device 100 is a large vehicle such as a truck, the braking distance is longer than that of an ordinary vehicle, so it is desirable to set the above-mentioned threshold value longer than that of an ordinary vehicle (for example, 10 m).

[0164] The user setting change unit 1126 allows the user 140 to change the criterion for determining whether or not to change the display angle of view to the second angle of view 131 in the display angle of view determination unit 1124. The criterion set (changed) by the user 140 is input from the user setting change unit 1126 to the display angle of view determination unit 1124.

[0165] The display angle of view changing unit 1122 generates a display image to be displayed on the display device 1130 according to the determination result by the display angle of view determining unit 1124. For example, when it is determined that the first angle of view 130 should be used, the display angle of view changing unit 1122 cuts out a rectangular sandwiched image (first image) from the image data corresponding to the first angle of view 130 and outputs it to the display device 1130.

[0166] Furthermore, when a following vehicle that satisfies a predetermined condition is present in the image data corresponding to the second angle of view 131, the display angle of view change unit 1122 outputs to the display device 1130 an image (second image) including the following vehicle.

[0167] The second image may include an image corresponding to the first region 201a. The display angle changing unit 1122 functions as a display control unit that performs display control to switch between a first display state in which the display device 1130 displays the first image and a second display state in which the display device 1130 displays the second image.

[0168] The display angle of view change unit 1122 cuts out an image by storing the image data output from the image processing unit 1121 in a storage unit (memory) such as a RAM, and reading out the image to be cut out from there.

[0169] The area in the image data corresponding to the first image is a rectangular area in the first angle of view 130 corresponding to the first area 201a. The area in the image data corresponding to the second image is a rectangular area including the rear vehicle in the second angle of view 131 corresponding to the second area 201b.

[0170] The display device 1130 has a display unit such as a liquid crystal display or an organic EL display, and displays the display image output from the display angle of view changing unit 1122. For example, the display device 1130 has a first display unit serving as an electronic rearview mirror arranged above the windshield (front glass) of the mobile device 100, and a second display unit serving as an operation panel (monitor) arranged below the windshield of the mobile device 100. These display units may be HUDs (Head Up Displays) that form virtual images on the windshield (front glass).

[0171] According to the above-mentioned configuration, the first image and the second image generated from the above-mentioned image data can be displayed on the first display unit and the second display unit, respectively. That is, in this embodiment, the first image corresponding to the first angle of view can be displayed on the first display unit, and the second image corresponding to the second angle of view including the first angle of view can be displayed on the second display unit. The first display unit may be configured to be used as a mirror when not used as a display by including, for example, a half mirror.

[0172] The second display unit may also function as a display for a navigation system or an audio system, for example. Note that the mobile device 100 is not limited to a vehicle such as an automobile, and may be a mobile body such as a ship, an aircraft, an industrial robot, or a drone.

[0173] Although the in-vehicle system 1101 according to this embodiment is used to display images to the user 140, it may be used for cruise control (including full-speed tracking function), automatic driving, and driving assistance that issues various warnings and displays to the driver. Furthermore, the in-vehicle system 1101 is not limited to a mobile device and can be applied to various devices that use object recognition, such as an intelligent transport system (ITS).

[0174] In addition, in the above-described in-vehicle system 1101, the above-described distance measuring device may be adopted as the imaging device 1102. In this case, the in-vehicle system 1101 may include a determination unit that determines the possibility of a collision with an object based on information on the distance to the object acquired by the imaging device 1102.

[0175] Also, a stereo camera having two imaging units 210 may be adopted as the imaging device 1102. In this case, even without using an imaging surface phase difference sensor, image data can be simultaneously acquired by each of the synchronized imaging units, and the same processing as described above can be performed by using the two image data. However, if the difference in imaging time between each imaging unit is known, each imaging unit does not need to be synchronized.

[0176] Furthermore, the above-described imaging device 1102 may be configured so that the resolution in the second angle of view (second region) is higher than the resolution in the first angle of view (first region) as necessary. That is, the number of pixels per unit angle of view in the first region may be smaller than the number of pixels per unit angle of view in the second region excluding the first region. Such a configuration is suitable for cases where it is desired to enlarge and capture an image of a subject around the center of the angle of view, such as when the imaging device 1102 is installed at the position of a side mirror of a vehicle.

[0177] Although the present invention has been described in detail based on the preferred embodiment, the present invention is not limited to the above embodiment, and various modifications are possible based on the spirit of the present invention, and are not excluded from the scope of the present invention. The above embodiment includes the following combinations.

[0178] (Configuration 1) A lens device comprising: a lens barrel housing a plurality of lenses; a pressing member contacting at least one of the lenses; a biased portion contacting the pressing member; and an elastic member sandwiched between the biased portion and the lens barrel in the optical axis direction, the biased portion being positioned radially inside the pressing member and outside the lens barrel.

[0179] (Configuration 2) The lens device according to configuration 1, wherein a portion of the biased portion on the subject side is held in contact with the lens barrel in the optical axis direction.

[0180] (Configuration 3) The biased portion is formed as a separate part from the pressing member, The lens device according to configuration 1 or 2, wherein the elastic member is inserted from the side of the lens barrel opposite to the subject side, and the pressing member and the biased portion are fixed together.

[0181] (Configuration 4) A lens device as described in configuration 3, characterized in that an outer diameter portion of the biased portion has a male thread portion, and an inner diameter portion of the pressing member has a female thread portion, and the pressing member and the biased portion are fixed by screwing the male thread portion and the female thread portion together.

[0182] (Configuration 5) The lens device described in configuration 4, characterized in that the biased portion has a concave or convex portion whose depth direction has a component in the optical axis direction on the image surface side of the lens barrel, and the pressing member has a concave or convex portion whose depth direction has a component in the optical axis direction on the subject side.

[0183] (Configuration 6) The lens device according to any one of configurations 1 to 5, wherein the elastic member is made of a metal material.

[0184] (Configuration 7) The lens device according to any one of configurations 1 to 6, wherein the lens barrel is made of a metal material.

[0185] (Configuration 8) A housing for holding the lens device according to any one of configurations 1 to 7, An optical device, wherein a portion of the lens device is exposed from the housing.

[0186] (Configuration 9) An imaging device comprising: the lens device according to any one of configurations 1 to 7; and an imaging element that images an object through the lens device.

[0187] (Configuration 10) An in-vehicle system comprising the imaging device according to configuration 9, and a display device that displays an image obtained based on an output of the imaging device.

[0188] (Configuration 11) The in-vehicle system described in Configuration 10, wherein the display device has a first display unit that displays a first image among the images corresponding to a first angle of view, and a second display unit that displays a second image corresponding to a second angle of view including the first angle of view.

[0189] (Configuration 12) A moving device comprising the imaging device according to configuration 9, the moving device being capable of holding and moving the imaging device.

[0190] (Configuration 13) A lens device comprising: a lens barrel that houses a lens; and a pressure ring that holds the lens, the lens barrel having a wall portion on the subject side of the lens; an elastic member that is clamped between the wall portion and a first lens that is positioned closest to the subject side of the lens; the first lens is held at a distance from the wall portion; and the pressure ring is screwed into the lens barrel on the opposite side of the optical axis direction from the wall portion and the first lens, and is held by being abutted against a predetermined contact surface.

[0191] (Configuration 14) The lens device according to configuration 13, wherein the wall portion is provided with a groove portion capable of accommodating the elastic member.

[0192] (Configuration 15) The lens device according to configuration 13 or 14, wherein the presser ring is threadedly engaged with and held by the outer periphery of the lens barrel.

[0193] (Configuration 16) The lens device according to any one of configurations 13 to 15, wherein the contact surface is provided on the lens barrel.

[0194] (Configuration 17) The lens device according to any one of configurations 13 to 16, further comprising a ring member that is held between the lens barrel and the pressing ring, the contact surface being provided on the ring member.

[0195] (Configuration 18) The lens device according to configuration 17, wherein the ring member is made of a metallic material.

[0196] (Configuration 19) The lens device according to any one of configurations 13 to 18, wherein the elastic member has an annular shape. [Explanation of symbols]

[0197] 101...Optical device 102, 202... Telescope unit 103... Enclosure 104 Electrical equipment 105...Subject 106 Windshield 11, 211... First lens 12, 212... 2nd lens 13, 213...Third lens 14, 214... 4th lens 15, 215... 5th lens 16, 216... Spacer 17, 217... Telescope tube 18, 218a, 218c... Retaining member 19... Forced part 20, 220... Elastic member 17a, 217a... Lens tube fitting part 18a, 218b, 218d... Pressing member fitting portion 17b, 217b...Wall section 218e... Retaining member groove 219a, 219b... Forced member 219c... Forced member groove 221... Adhesive

Claims

1. a lens barrel that houses a plurality of lenses; a holding member that contacts at least one of the plurality of lenses; a biased portion fixed to the holding member; an elastic member sandwiched between the biased portion and the lens barrel in the optical axis direction; A lens device characterized in that the biased portion is arranged radially inside the holding member and outside the lens barrel, and is biased by the elastic member toward the side opposite the lens barrel in the optical axis direction.

2. 2. The lens device according to claim 1, wherein a portion of the biased portion on the subject side is in contact with the lens barrel in the optical axis direction.

3. 2. The lens device according to claim 1, wherein the biased portion is formed as a separate part from the holding member.

4. A lens device as described in claim 1, characterized in that each of the holding member and the force-receiving portion includes a threaded portion that screws into each other.

5. 5. The lens device according to claim 4, wherein the biased portion includes a concave or convex portion formed toward the image plane side.

6. A lens device as described in Claim 4, characterized in that the holding member includes a concave or convex portion formed toward the subject side.

7. 2. The lens device according to claim 1, wherein the elastic member is made of a metal material.

8. 2. The lens device according to claim 1, wherein the lens barrel is made of a metal material.

9. a housing for holding the lens device according to any one of claims 1 to 8; An optical device, wherein a part of the lens device is exposed from the housing.

10. 9. An imaging device comprising: the lens device according to claim 1; and an imaging element that captures an image of an object via the lens device.

11. 11. An in-vehicle system comprising: the imaging device according to claim 10; and a display device that displays an image obtained based on an output of the imaging device.

12. 12. The in-vehicle system according to claim 11, wherein the display device has a first display unit that displays a first image corresponding to a first angle of view among the images, and a second display unit that displays a second image corresponding to a second angle of view that includes the first angle of view.

13. A moving device comprising the imaging device according to claim 10, and capable of moving while holding the imaging device.

Images