Telescope tube unit and optical device

Abstract

The present invention provides a telescope tube unit that offers excellent waterproofing and suppresses deterioration of rattling, tightening, and assembly quality due to temperature changes. [Solution] The lens barrel unit comprises a lens barrel that houses a plurality of lenses, a first lens among the plurality of lenses that is closest to the subject, and a second lens located next to the subject after the first lens, and an elastic member disposed between the first lens and the second lens, the image plane side of the first lens being in contact with the lens barrel in the optical axis direction, the elastic member being compressed and held, and a separation means provided so that at least a portion of the elastic member and the second lens are not in contact.

Description

Technical Field

[0001] The present invention relates to a lens barrel unit, an optical device, and the like.

Background Art

[0002] For example, optical devices mounted on automobiles include cameras that perform sensing for realizing driving assistance and autonomous driving functions, and image the surroundings of the automobile. Further, as an optical device having a sensing function, there is LiDAR (Light Detection And Ranging).

[0003] These devices each have a lens barrel that holds a lens as an optical element. When a lens is held in a lens barrel, if the environmental temperature changes due to the difference in expansion / contraction amount caused by the difference in linear expansion coefficients between the lens and the lens barrel, there is a possibility that clearance (play) or tightening occurs.

[0004] Changes in the holding position of the lens due to the generated play, and surface deformation of the lens due to the generated tightening may cause deterioration of optical performance and aging deterioration of components.

[0005] In-vehicle cameras and LiDAR are required to guarantee excellent performance and functions over the entire temperature range under temperature environments that vary across a wide range. Furthermore, in-vehicle cameras usually do not include an autofocus mechanism for reasons of cost and ensuring high reliability.

[0006] Higher performance and higher functions than currently available are demanded for driving assistance and autonomous driving functions of automobiles, and it is considered that the optical system of in-vehicle cameras, which serve as the "eyes" of automobiles, will be further required to become more complicated and higher in function.

[0007] As the optical system of an in-vehicle camera becomes more complicated and higher in function, the number of optical elements also increases, and it is considered that the play and tightening between the retaining ring, the lens barrel and the lens, which occur due to temperature changes, may become even more significant.

[0008] In contrast, there is a configuration in which an elastic member is sandwiched between the retaining ring and the lens for support, and is pre-compressed to the required amount during assembly at room temperature to provide elasticity and eliminate looseness at high temperatures.

[0009] For example, Patent Document 1 discloses a configuration in which an elastic member is placed between the lenses and assembled in a compressed state, thereby preventing looseness and tightening in the optical axis direction due to temperature changes. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2016-224388 [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] However, in the conventional examples disclosed in the aforementioned patent documents, the distance between the lenses sandwiching the elastic member changes due to variations in the pressing force used to hold the lens closest to the subject during lens barrel assembly and variations in the dimensions of the elastic member. In other words, there is a possibility that variations in optical performance due to individual differences in cameras will become large.

[0012] Furthermore, in-vehicle cameras are not limited to cameras that monitor and sense the area in front of the vehicle; many are mounted on the exterior of the vehicle to monitor and sense the area around and behind the vehicle. In particular, exterior-mounted cameras need to be waterproof to maintain their functionality even in rainy weather or after washing the car.

[0013] If an elastic component is tightly fitted between the lenses for waterproofing, the air between the lenses will be sealed, and when compressing the elastic component, a force is required to compress the air between the lenses in addition to the elastic force of the component, which may degrade the ease of assembly.

[0014] Therefore, one of the objectives of the present invention is to provide a lens barrel unit that has excellent waterproofing properties and can suppress rattling, tightening, and assembly deterioration due to temperature changes. [Means for solving the problem]

[0015] To achieve the above object, a lens barrel unit according to one aspect of the present invention is: a lens barrel that houses a plurality of lenses; a first lens that is closest to the object side among the plurality of lenses; a second lens positioned on the object side next to the first lens, comprising an elastic member disposed between the first lens and the second lens, an image plane side of the first lens is in contact with the lens barrel in an optical axis direction, the elastic member is compressed and held, the lens barrel unit comprising spacing means that brings at least a part of the elastic member and the second lens into non-contact with each other. Effects of the Invention

[0016] According to the present invention, it is possible to provide a lens barrel unit that is excellent in water resistance and can suppress play, tightening, and assemblability deterioration caused by temperature changes. Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is a schematic diagram of an optical device 101 according to Embodiment 1 of the present invention. [Figure 2] FIG. 2 is a cross-sectional view illustrating an example of the structure of the lens barrel unit 102 according to Embodiment 1. [Figure 3] FIG. 3 is a view illustrating an example of the shape of a spacer 19 according to Embodiment 1. [Figure 4] FIG. 4 is a cross-sectional view illustrating an example of a lens barrel unit structure in a case where the first lens 11 is adhered and fixed to the lens barrel. [Figure 5] FIG. 5 is a cross-sectional view illustrating an example of the structure of a lens barrel unit 202 according to Embodiment 2. [Figure 6] FIG. 6 is a view illustrating an example of the shape of a second lens 212 according to Embodiment 2. Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments. In each drawing, the same reference numerals are assigned to the same members or elements, and duplicate descriptions are omitted or simplified. <Embodiment 1>

[0019] FIG. 1 is a schematic diagram of an optical device 101 according to Embodiment 1 of the present invention. The optical device 101 is constituted by a lens barrel unit 102, a housing 103, and an image processing device 104. For example, when the optical device 101 is an in-vehicle camera, the lens barrel unit 102 functions as an imaging optical system, captures an image of a subject 105 via the imaging optical system with an image sensor, processes an image signal with the image processing device 104, and acquires a subject image around the vehicle.

[0020] Here, for example, a CCD or CMOS image sensor functions as an imaging means that captures a subject image via the lens barrel unit 102 and converts the captured subject image into an electrical signal.

[0021] The electrical signal converted by the image sensor is converted into digital image data. The obtained digital image data is used in driving assistance and automatic driving systems. In addition, a part of the lens barrel unit 102 of the optical device 101 such as an in-vehicle camera on the subject side is exposed from the housing 103, and the optical device 101 is installed around an automobile. That is, the housing 103 holds the lens barrel unit, and a part of the lens barrel unit 102 closest to the subject is exposed from the housing 103.

[0022] FIG. 2 is a cross-sectional view illustrating an example of the structure of the lens barrel unit 102 according to Embodiment 1. The lens barrel unit 102 includes a lens barrel 16 that accommodates a plurality of lenses. That is, the lens barrel unit 102 includes a first lens 11, a second lens 12, a third lens 13, and a fourth lens 14 from the subject side (the left side in FIG. 2). That is, the lens barrel unit 102 includes at least the first lens 11 closest to the subject among the plurality of lenses, and the second lens positioned next to the first lens on the subject side.

[0023] Furthermore, the lens barrel unit 102 includes a spacer 15 positioned between the second lens 12 and the third lens 13, a biasing part 17 that contacts the first lens 11 and biases the first lens 11 toward the lens barrel 16, and an elastic member 18 positioned between the first lens and the second lens. In this embodiment, the first lens 11, the second lens 12, the third lens 13, and the fourth lens 14 are glass lenses.

[0024] Furthermore, the spacer 15, lens barrel 16, and biasing part 17 are made of metal. Note that the number of lenses, the number of spacers, and the materials of the lenses, spacers, and lens barrel can be arbitrarily set according to the application, and are not limited to the example of this embodiment. For example, the first lens 11 may be a spherical glass lens, and the second lens 12, third lens 13, and fourth lens 14 may be resin lenses. Also, the biasing part 17 may be made of resin material.

[0025] Furthermore, the lens barrel unit 102 is equipped with an "aperture diaphragm" that limits the amount of transmitted light and determines the F-number, which is an indicator of brightness, and a "light-shielding diaphragm" that blocks light rays that cause ghosting and light rays that cause aberrations, but these are omitted in Figure 2 for the sake of simplicity. In addition, the surfaces of these first lens 11, second lens 12, third lens 13, and fourth lens 14 may be provided with an anti-reflective coating, hydrophilic coating, water-repellent coating, etc., as needed.

[0026] The elastic member 18 is made of a rubber material such as silicone rubber, which is heat-resistant so as not to deteriorate even in the harsh in-vehicle temperature environment. The elastic member 18 is held between the first lens 11 and the second lens 12 in the direction of the optical axis O.

[0027] Here, the assembly method of the lens barrel unit 102 will be described. The lens barrel unit 102 houses and holds the fourth lens 14, the third lens 13, the spacer 15, and the second lens 12 inside the lens barrel 16, and houses the spacer 19 and elastic member 18 as separation means on the subject side of the second lens 12.

[0028] Subsequently, the first lens 11 is inserted, and the first lens 11 is further biased by the biasing part 17, and the elastic member 18 is compressed and held in place to assemble the lens barrel unit 102. The elastic member 18 is made of a rubber material such as silicone rubber, and the space between the first lens 11 and the second lens 12 is sealed by the elastic member 18. That is, the elastic member 18 is a sealing material including, for example, an O-ring, and a sealed structure is formed by contact with the inner diameter of the lens barrel 16.

[0029] During assembly, compressing the elastic member 18 requires not only the elastic force of the elastic member 18 but also the force to compress the sealed air. Therefore, the number of steps required to compress the elastic member 18 to the required amount increases. In this embodiment, a spacer 19 is provided as a means of separation to ensure that at least a portion of the elastic member 18 and the second lens 12 are not in contact.

[0030] Figure 3 illustrates an example of the shape of the spacer 19 in Embodiment 1. The spacer 19 has a shape with irregularities that form a lens contact portion 19a that contacts the second lens 12 and a lens non-contact portion 19b that does not contact the second lens 12.

[0031] Furthermore, the spacer 19 has an outer diameter portion 19c that can contact the inner diameter of the elastic member 18. That is, the separation means in this embodiment includes a spacer having an outer diameter that can contact the inner diameter of the elastic member 18 and an uneven shape that partially does not contact the second lens 12. The spacer 19 is made of, for example, a resin material.

[0032] By inserting a spacer 19 between the elastic member 18 and the second lens 12, when the elastic member 18 is compressed during assembly, it becomes possible to allow air between the first lens 11 and the second lens 12 to be vented from the lens non-contact portion 19b to the image plane side from the second lens 12 onward.

[0033] Therefore, the force required to compress the air between the first lens 11 and the second lens 12 to compress the elastic member 18 can be reduced, thereby suppressing a decrease in ease of assembly. In addition, by providing an outer diameter portion 19c on the spacer 19, it becomes possible to guide the position of the elastic member 18, and the elastic member 18 can be held in the desired position.

[0034] Furthermore, it is also effective to provide an air vent groove (not shown) in the mating diameter portion of the lens barrel 16 on the image plane side of the second lens 12, so that the compressed air from the second lens 12 onwards can escape more easily.

[0035] In this embodiment, a diameter difference is provided between the inner diameter of the lens barrel 16 that houses the second lens 12 and the outer diameter of the first lens 11, and the image plane side of the first lens 11 is configured to contact the lens barrel 16 in the direction of the optical axis O. Furthermore, the biasing portion 17 may be, for example, a retaining ring that is screwed onto the lens barrel 16, or a crimping structure that is integrated with the lens barrel 16 by roller crimping or thermal crimping.

[0036] Figure 4 is a cross-sectional view illustrating an example of a lens barrel unit structure when the first lens 11 is fixed to the lens barrel by adhesive, showing the lens barrel unit 102 when the biasing part 17 is made of adhesive 17a. As shown in Figure 4, the first lens 11 may also be fixed to the lens barrel 16 by adhesive 17a. That is, the biasing part 17 may fix the first lens and the lens barrel 16 by adhesive.

[0037] In this embodiment, the position of the first lens 11 is determined by contact with the lens barrel 16 in the direction of the optical axis O. At this time, by compressing the elastic member 18 by the required amount, the lenses 12, 13, 14 and the spacer 15 are held in the lens barrel 16 in a state of constant pressure due to the reaction force of the elastic force of the elastic member 18.

[0038] The elastic member 18 is positioned between the first lens 11 and the second lens 12, and the outer diameter of the elastic member 18 is in contact with the inner diameter of the lens barrel 16, thereby creating a sealed structure on the subject side. This prevents water droplets and moisture from entering from the subject side towards the image plane side (right side in Figure 4) of the first lens 11.

[0039] Furthermore, the elastic force of the elastic member 18 constantly presses the first lens 11 against the lenses 12, 13, and 14, as well as the spacer 15. Therefore, when the ambient temperature drops from the time of assembly, the elastic member 18 can absorb the lens deformation caused by tightening resulting from the difference in the coefficient of linear expansion between the lens barrel 16 and the lenses.

[0040] In this embodiment, the lens barrel 16 is made of, for example, an aluminum alloy, and its coefficient of thermal expansion is 26 × 10⁻⁶ / °C. The first lens 11, second lens 12, third lens 13, and fourth lens 14 are made of glass, and their coefficients of thermal expansion are 7 × 10⁻⁶ / °C.

[0041] Furthermore, the length of the spacer 15 in the optical axis direction is set to 1.5 mm, and the length of the lens barrel 16 from the wall portion 16a to the contact portion 16b with the first lens 11 in the optical axis direction is set to 6 mm. The thickness of the second lens 12 in the optical axis direction is set to 1.5 mm, and the thickness of the third lens 13 and the fourth lens 14 in the optical axis direction is set to 1 mm.

[0042] In this case, a 1°C change in temperature causes a 0.1 μm difference in the distance between the first lens 11 and the second lens 12. Therefore, in an environment where the ambient temperature drops by 60°C from the time of assembly, a 6 μm lens deformation occurs in the optical axis direction, but this deformation can be absorbed by the elastic member 18.

[0043] Furthermore, in environments where the ambient temperature rises by 60°C above the assembly temperature, a 6 μm gap will occur in the optical axis direction. However, by assembling the system with the elastic member 18 compressed to the required extent, the first lens 11 and the second lens 12 are constantly pressed and held in place by the reaction force of the elastic member 18's elastic force, thus absorbing this gap.

[0044] Furthermore, by making the inner diameter of the lens barrel 16 larger than the outer diameter of the lenses 11, 12, 13, and 14, a portion of the lens outer diameter does not come into contact with the inner diameter of the lens barrel. This makes it possible to suppress the occurrence of radial tightening of the lens by the lens barrel 16 due to the difference in the linear expansion coefficients of the lens barrel and the lens, even in environments where the temperature is lower than during assembly.

[0045] In this embodiment, the elastic member 18 is arranged between the first lens 11 and the second lens 12, and the first lens 11 is in contact with the lens barrel 16 in the direction of the optical axis O. This makes it possible to suppress the intrusion of water droplets and moisture from the subject side.

[0046] Therefore, when installing an optical device 101 in which a part of the lens barrel unit 102 is exposed, as shown in Figure 1, on a vehicle body exposed to the outside air, its function can be maintained even in rainy weather or after washing the car.

[0047] Furthermore, by assembling the components with the elastic member 18 in a compressed state, the first lens 11, the lenses 12, 13, and 14, and the spacer 15 can be held in a constantly pressed state by the reaction force due to the elastic force of the elastic member 18.

[0048] With this configuration, when the lens barrel unit 102 undergoes a temperature change, the elastic member 18 absorbs the tightening and looseness that occurs on the lens due to the difference in the coefficient of linear expansion, thereby applying a constant pressure to hold the lens in place.

[0049] Furthermore, by providing a configuration in which a spacer 19 having a lens non-contact portion 19b is placed between the elastic member 18 and the second lens 12, when the elastic member 18 is compressed during assembly, it becomes possible to allow air between the first lens 11 and the second lens 12 to pass through to the second lens 12 and beyond.

[0050] Therefore, the force required to compress the elastic member 18 can be reduced, and the increase in the number of steps required to compress the elastic member 18 to the required amount can be suppressed.

[0051] In this embodiment 1, the lens barrel unit 102 is described as having a structure composed of four lenses, but the number of lenses can be any number of two or more. Furthermore, although this is applied to an in-vehicle camera used for driver assistance and autonomous driving, it is not limited to this and may be applied to optical devices other than in-vehicle cameras.

[0052] <Embodiment 2> Embodiment 1 described an example of a configuration in which a spacer is provided between the elastic member and the second lens, but Embodiment 2 describes a lens barrel unit in which the second lens has a shape in which it does not come into contact with the elastic member.

[0053] Figure 5 is a cross-sectional view illustrating an example of the structure of the lens barrel unit 202 of Embodiment 2. The lens barrel unit 202 includes, for example, a lens barrel 216 that houses a plurality of lenses. That is, the lens barrel unit 202 has a first lens 211, a second lens 212, a third lens 213, and a fourth lens 214 from the subject side, and also has a spacer 215 positioned between the second lens 212 and the third lens 213.

[0054] Furthermore, the lens barrel unit 202 has a biasing portion 217 and an elastic member 218 that contact the first lens 211 and hold the lens in the lens barrel 216. In this embodiment, the first lens 211 is made of glass, and the second lens 212, third lens 213, and fourth lens 214 are plastic molded lenses. That is, in this embodiment, at least the second lens 212 is made of plastic material.

[0055] Furthermore, the spacer 215, lens barrel 216, and biasing part 217 are made of, for example, metal. The number of lenses, the number of spacers, and the materials of the lenses, spacers, and lens barrel can be arbitrarily determined depending on the application.

[0056] For example, the first lens 211 may be a spherical glass lens, and the second lens 212, third lens 213, and fourth lens 214 may be glass molded lenses. Also, the biasing part 217 may be made of a resin material.

[0057] Furthermore, the lens barrel unit 202 is equipped with an "aperture diaphragm" that limits the amount of transmitted light and determines the F-number, which is an indicator of brightness, and a "light-shielding diaphragm" that blocks light rays that cause ghosting and light rays that cause aberrations, but these are omitted in Figure 5 for the sake of simplicity. In addition, the surfaces of these first lens 211, second lens 212, third lens 213, and fourth lens 214 may be provided with an anti-reflective coating, hydrophilic coating, water-repellent coating, etc., as needed.

[0058] The elastic member 218 is made of a rubber material such as silicone rubber, which is heat-resistant so that its physical properties are not affected even in the harsh in-vehicle temperature environment. The elastic member 218 is held between the first lens 211 and the second lens 212 in the direction of the optical axis O.

[0059] The assembly method for the lens barrel unit 202 will now be explained. The lens barrel unit 202 is assembled by housing and holding the fourth lens 214, the third lens 213, the spacer 215, and the second lens 212 inside the lens barrel 216, and then housing the elastic member 218 on the subject side of the second lens 212. After that, the first lens 211 is inserted, and the first lens 211 is further biased by the biasing part 217, and the elastic member 218 is compressed and held in place to assemble the lens barrel unit 202.

[0060] Furthermore, a difference in diameter is provided between the inner diameter of the lens barrel 216, which houses the outer diameter of the second lens 212, and the outer diameter of the first lens 211, so that the first lens 211 contacts the lens barrel 216 in the direction of the optical axis O.

[0061] Furthermore, the biasing portion 217 may be, for example, a retaining ring that is screwed onto the lens barrel 216, or it may be integrated with the lens barrel 16 and secured by roller crimping, thermal crimping, or adhesive. The position of the first lens 211 is determined by contact with the lens barrel 216 in the direction of the optical axis O.

[0062] At this time, by compressing the elastic member 218 to the required amount, the lenses 212, 213, 214 and the spacer 215 are constantly pressed against the lens barrel 216 by the reaction force of the elastic force of the elastic member 218.

[0063] The elastic member 218 is positioned between the first lens 211 and the second lens 212, and the outer diameter of the elastic member 218 is in contact with the inner diameter of the lens barrel 216, creating a sealed structure on the image plane side (right side in Figure 5). This prevents water droplets and moisture from entering from the subject side towards the image plane side of the first lens 211.

[0064] Furthermore, the elastic force of the elastic member 218 constantly presses against the first lens 211, the lenses 212, 213, and 214, and the spacer 215. Therefore, when the ambient temperature becomes high from the time of assembly, the elastic member 218 can absorb the lens deformation caused by tightening due to the difference in the coefficient of linear expansion between the lens barrel 216 and the lenses.

[0065] In this embodiment, the lens barrel 216 and spacer 215 are made of aluminum alloy, and their coefficient of thermal expansion is 26 × 10⁻⁶ / °C. The first lens 11 is made of glass, and its coefficient of thermal expansion is 7 × 10⁻⁶ / °C. The second lens 212, third lens 213, and fourth lens 214 are made of plastic molded lenses, and their coefficient of thermal expansion is 58 × 10⁻⁶ / °C.

[0066] The optical axis length of the spacer 215 is set to 1.5 mm, and the optical axis length from the wall portion 216a of the lens barrel 216 to the contact portion 216b with the first lens 211 is set to 6 mm. The optical axis thickness of the second lens 212 is set to 1.5 mm, and the optical axis thickness of the third lens 213 and the fourth lens 214 is set to 1 mm. In this case, a 1°C change in temperature causes a gap of 0.09 μm between the first lens 211 and the second lens 212.

[0067] This means that in an environment where the ambient temperature rises by 60°C above the assembly temperature, a lens deformation of 5.4 μm will occur in the optical axis direction, but the elastic member 218 can absorb this deformation.

[0068] Furthermore, in environments where the ambient temperature drops by 60°C from the time of assembly, a 5.4 μm gap will occur in the optical axis direction. However, by assembling the system with the elastic member 218 compressed to the required extent, the first lens 211 and the second lens 212 are constantly pressed and held in place by the reaction force of the elastic member 218's elastic force, thus absorbing this gap.

[0069] Furthermore, by making the inner diameter of the lens barrel 216 larger than the outer diameter of the lenses 211, 212, 213, and 214, a portion of the lens outer diameter is not in contact with the inner diameter of the lens barrel. That is, at least the outer diameter of the second lens is not in contact with the inner diameter of the lens barrel 216 in part.

[0070] This makes it possible to suppress the occurrence of radial tightening of the lens barrel 216 onto the plastic molded lens due to the difference in the coefficient of linear expansion between the lens barrel and the lens, even in environments where the temperature rises from the time of assembly.

[0071] By placing a compressed elastic member 218 between the first lens 211 and the second lens 212, and by using a rubber material such as silicone rubber for the elastic member 218, the space between the first lens 211 and the second lens 212 is sealed.

[0072] During assembly, compressing the elastic member 218 requires not only the elastic force of the elastic member 218 but also the force to compress the sealed air. This can increase the number of steps required to compress the elastic member 218 to the required amount. Therefore, in this embodiment, the second lens 212 is provided with an uneven shape that acts as a means of separation, without contacting the elastic member 218.

[0073] Figure 6 illustrates an example of the shape of the second lens 212 in Embodiment 2. The second lens 212 has a shape that includes an elastic member contact portion 212a that can contact the elastic member 218 and an elastic member non-contact portion 212b that does not contact the elastic member 218. That is, the separation means includes an uneven shape provided on the subject side of the second lens 212, which is partially non-contact with the elastic member 218.

[0074] Thus, in this embodiment, the second lens 212 is provided with a shape that forms a non-contact portion 212b for the elastic member. This makes it possible to vent the air between the first lens 211 and the second lens 212 from the non-contact portion 212b to the image plane side from the second lens 212 onward when the elastic member 218 is compressed during assembly.

[0075] Therefore, the force required to compress the air between the first lens 211 and the second lens 212, which is necessary to compress the elastic member 218, can be reduced, thereby suppressing a decrease in ease of assembly.

[0076] In this embodiment, the elastic member 218 is positioned between the first lens 211 and the second lens 212, biasing the first lens 211 in the direction of the optical axis O and bringing it into contact with the lens barrel 216.

[0077] This prevents water droplets and moisture from entering from the subject side. Therefore, when installing an optical device 101 in which part of the lens barrel unit 202 is exposed, as shown in Figure 1, on a car body exposed to the outside air, its function can be maintained even in rainy weather or after washing the car.

[0078] Furthermore, because the elastic member 218 is assembled in a compressed state, the first lens 211, the lenses 212, 213, 214, and the spacer 215 can be held in a constantly pressed state by the reaction force due to the elastic force of the elastic member 218.

[0079] With this configuration, when the lens barrel unit 202 experiences temperature changes, the elastic member 218 absorbs the tightening and looseness that occurs on the lens due to the difference in the coefficient of linear expansion, thereby providing a constant pressure to hold the lens in place.

[0080] Furthermore, in Embodiment 2, by configuring the second lens 212 to have a non-contact portion 212b for the elastic member, it becomes possible to allow the air between the first lens 211 and the second lens 212, which is necessary when compressing the elastic member 218 during assembly, to pass through to the second lens 212 and beyond. Therefore, the force required to compress the elastic member 218 can be reduced, and the increase in the number of steps required to compress the elastic member 218 to the required amount can be suppressed.

[0081] In Embodiment 2, a structure is described in which the lens barrel unit 202 consists of four lenses, but the number of lenses can be any number of two or more. Furthermore, although it is applied to in-vehicle cameras used for driver assistance and autonomous driving, it is not limited to these and may be applied to optical devices other than in-vehicle cameras.

[0082] Although the present invention has been described in detail above based on its preferred embodiments, the present invention is not limited to these specific embodiments, and various forms that do not depart from the spirit of the invention are also included in the present invention. Some of the above embodiments may be combined as appropriate.

[0083] (Configuration 1) A lens barrel unit comprising a lens barrel that houses a plurality of lenses, a first lens among the plurality of lenses that is closest to the subject, and a second lens located next to the subject after the first lens, an elastic member disposed between the first lens and the second lens, the image plane side of the first lens being in contact with the lens barrel in the direction of the optical axis, the elastic member being compressed and held, and a separation means provided so that at least a part of the elastic member and the second lens are not in contact.

[0084] (Configuration 2) The lens barrel unit according to Configuration 1, characterized in that a difference in diameter is provided between the inner diameter of the lens barrel in which the second lens is housed and the outer diameter of the first lens.

[0085] (Configuration 3) The lens barrel unit according to Configuration 1 or 2, characterized in that the elastic member is a sealing material including an O-ring, and a sealed structure is formed by contact with the inner diameter of the lens barrel.

[0086] (Configuration 4) The lens barrel unit according to any one of Configurations 1 to 3, characterized in that the separating means includes a spacer having an outer diameter that can contact the inner diameter of the elastic member and an uneven shape that partially does not contact the second lens.

[0087] (Configuration 5) The lens barrel unit according to Configuration 4, characterized in that the spacer is made of resin material.

[0088] (Configuration 6) The lens barrel unit according to any one of Configurations 1 to 5, characterized in that the separating means includes an uneven shape provided on the subject side of the second lens, in which a portion of the elastic member does not come into contact.

[0089] (Configuration 7) The lens barrel unit according to any one of Configurations 1 to 6, characterized in that the second lens is made of plastic material.

[0090] (Configuration 8) The lens barrel unit according to any one of Configurations 1 to 7, characterized in that the outer diameter of the second lens is not in contact with a portion of the inner diameter of the lens barrel.

[0091] (Configuration 9) The lens barrel unit according to any one of Configurations 1 to 8, characterized in that the first lens is held in the lens barrel by a biasing part that biases the first lens.

[0092] (Configuration 10) The lens barrel unit according to Configuration 9, characterized in that the biasing portion includes a retaining ring that is screwed onto the lens barrel.

[0093] (Configuration 11) The lens barrel unit according to configuration 9 or 10, characterized in that the biasing portion has a crimping structure that crimps a part of the lens barrel.

[0094] (Configuration 12) The lens barrel unit according to any one of Configurations 9 to 11, characterized in that the biasing part fixes the first lens and the lens barrel by adhesive.

[0095] (Configuration 13) An optical device characterized by comprising a lens barrel unit described in any one of Configurations 1 to 12, and an imaging means for capturing an image of a subject through the lens barrel unit.

[0096] (Configuration 14) An optical device comprising a housing that holds the lens barrel unit described in Configuration 13, wherein the portion of the lens barrel unit closest to the subject is exposed from the housing. [Explanation of symbols]

[0097] 101...Optical device 102, 202... Telescope tube units 103... cabinet 104..Image processing device 105... Subject 11, 211...First lens 12,212...Second lens 13, 213... Third lens 14, 214... Fourth lens 15, 215... Spacer 16, 216... Telescope tube 17, 217..... biasing section 17a.. Adhesive 18, 218... Elastic members 16a, 216a...Wall section 16b, 216b...Contact part 19..Spacer 19a...Lens contact area 19b...Non-contact part of the lens 19c...Outer diameter part 212a····Elastic member contact area 212b... Non-contact portion of elastic member

Claims

1. A lens barrel that houses multiple lenses, The first lens, which is closest to the subject among multiple lenses, It comprises a second lens located next to the first lens, on the subject side, It has an elastic member positioned between the first lens and the second lens, The image plane side of the first lens is in contact with the lens barrel in the direction of the optical axis, The elastic member is compressed and held, A lens barrel unit characterized by comprising a separation means that prevents at least a portion of the elastic member and the second lens from contacting each other.

2. The lens barrel unit according to claim 1, characterized in that a difference in diameter is provided between the inner diameter of the lens barrel in which the second lens is housed and the outer diameter of the first lens.

3. The lens barrel unit according to claim 1, characterized in that the elastic member is a sealing material including an O-ring, and a sealed structure is formed by contact with the inner diameter of the lens barrel.

4. The lens barrel unit according to claim 1, characterized in that the separating means includes a spacer having an outer diameter that can contact the inner diameter of the elastic member and an uneven shape that partially does not contact the second lens.

5. The lens barrel unit according to claim 4, characterized in that the spacer is made of a resin material.

6. The lens barrel unit according to claim 1, characterized in that the separating means includes an uneven shape provided on the subject side of the second lens, in which a portion of it does not come into contact with the elastic member.

7. The lens barrel unit according to claim 1, characterized in that the second lens is made of a plastic material.

8. The lens barrel unit according to claim 1, characterized in that the outer diameter of the second lens is not in contact with a portion of the inner diameter of the lens barrel.

9. The lens barrel unit according to claim 1, characterized in that the first lens is held in the lens barrel by a biasing part that biases the first lens.

10. The lens barrel unit according to claim 9, characterized in that the biasing portion includes a retaining ring that is screwed onto the lens barrel.

11. The lens barrel unit according to claim 9, characterized in that the biasing portion has a crimping structure that crimps a part of the lens barrel.

12. The lens barrel unit according to claim 9, characterized in that the biasing portion fixes the first lens and the lens barrel by adhesive.

13. A lens barrel unit according to any one of claims 1 to 12, An optical device characterized by having an imaging means for capturing an image of a subject via the lens barrel unit.

14. The housing comprises a housing for holding the lens barrel unit as described in claim 13, An optical device characterized in that the portion of the lens barrel unit closest to the subject is exposed from the housing.

Images