Lens unit and camera module

Abstract

The present invention addresses the problem of providing a lens unit provided with a heater, which has advantages in terms of cost and quality. [Solution] A lens unit (101A) is provided with a heater (8) that is located in a step-facing region (S1bB) included in a second surface (S1b) within a lens barrel (2A), the second surface being located on the eyepiece side of a spacer (S1) that is located between a first lens (L1) and a second lens (L2).

Description

Technical Field

[0001] The present invention relates to a lens unit and a camera module. Background Art

[0002] In recent years, in-vehicle cameras have been installed in vehicles for purposes such as assisting driving, preventing collisions, and recording driving. Some of such in-vehicle cameras are arranged inside the vehicle, and some are arranged outside the vehicle. For in-vehicle cameras arranged outside the vehicle, there is an increasing need to install a heater on the in-vehicle lens to melt ice and snow adhering to the lens closest to the object side or to remove fog. The in-vehicle camera also needs to have versatility to ensure the camera function under all conditions (weather, etc.), and the lens heater is considered an effective solution to prevent icing on the lens, especially in cold regions.

[0003] For example, the lens assembly of Patent Document 1 includes an objective lens, which is provided with a first surface facing the object side of the lens assembly and a second surface opposite to the first surface, and is also provided with a heating assembly, which has an annular heating element arranged on the second surface of the objective lens.

[0004] In addition, the imaging device of Patent Document 2 is configured to include: a heater member for heating the top lens, where the top lens refers to the lens closest to the subject side among the plurality of lenses included in the lens unit; and a reflection suppression material, which is provided between the region outside the effective region of the top lens and the heater member and suppresses light reflection. The reflection suppression material is configured to laminate a first reflection suppression material and a second reflection suppression material, where the first reflection suppression material is arranged on the top lens side and has a concavo-convex surface, and the second reflection suppression material is arranged on the heater member side.

[0005] In addition, the lens unit of Patent Document 3 is configured such that the first lens closest to the object side has an object-side lens surface, an image-side lens surface, and an image-side flange surface surrounding the image-side lens surface, and the first accommodating portion for accommodating the first lens includes a restricting portion for restricting the position of the first lens in the optical axis direction. Regarding the image-side flange surface, a flexible printed circuit board having a heater is arranged on the image-side flange surface of the first lens having an inner peripheral region where a flexible printed circuit board is arranged and an outer peripheral region abutting against the restricting portion. The lens unit of Patent Document 3 has a heater arranged on the image-side flange surface of the first lens, and the first lens and the second lens are press-fitted and fixed to each other.

[0006] In addition, Patent Document 4 discloses a lens unit in which a heater is disposed between lenses. In this configuration, the lenses are fitted to each other, and / or an optical element other than the lenses constituting the lens group is fitted to the lens, and / or the optical elements are fitted to each other to perform optical positioning. Accordingly, an insertion space for inserting a power supply unit of the heater is ensured in the optical axis direction between the lens barrel and the lens and / or the optical element on the outer side in the radial direction of the fitting region.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: US Patent No. 11,086,092 Specification

[0010] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2021-162730

[0011] Patent Document 3: Japanese Unexamined Patent Application Publication No. 2022-18285

[0012] Patent Document 4: Japanese Unexamined Patent Application Publication No. 2023-128223 Summary of the Invention

[0013] Problems to be Solved by the Invention

[0014] As described above, various technologies are being developed, and in order to further address the contradictions or various mounting configurations caused by the installation of a heater, a new method for a lens unit equipped with a heater is urgently needed.

[0015] An object of one aspect of the present invention is to realize a lens unit equipped with a heater that has advantages in terms of cost and quality.

[0016] Means for Solving the Problems

[0017] To solve the above problems, a lens unit according to one aspect of the present invention includes: a first lens closest to the objective lens side; a second lens on the eyepiece side of the first lens; a spacer located between the first lens and the second lens, a first surface of the spacer on the objective lens side being in contact with the first lens and a second surface of the spacer on the eyepiece side being in contact with the second lens; and a lens barrel that houses at least the first lens, the second lens, and the spacer. The spacer includes, on the second surface, a second lens contact region in contact with the second lens and a second lens non-contact region disposed closer to the outer diameter direction than the second lens contact region and not in contact with the second lens. The heater is installed in the second lens non-contact region of the lens unit.

[0018] To solve the above problems, a camera module according to one embodiment of the present invention includes the above lens unit and an imaging element.

[0019] Advantages of the Invention

[0020] According to one embodiment of the present invention, a lens unit with a heater can be provided, which has advantages in terms of cost and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view schematically showing the configuration of the lens unit according to Embodiment 1 of the present invention.

[0022] Figure 2 It is a view schematically showing the configuration of the camera module according to Embodiment 1 of the present invention.

[0023] Figure 3 It is a cross-sectional view schematically showing the configuration of the lens unit according to Embodiment 2 of the present invention.

[0024] Figure 4 It is a cross-sectional view schematically showing the configuration of the lens unit according to Embodiment 3 of the present invention.

[0025] Figure 5 It is a cross-sectional view schematically showing the configuration of the lens unit according to Embodiment 4 of the present invention.

[0026] Figure 6 It is a cross-sectional view schematically showing the configuration of the lens unit according to Embodiment 5 of the present invention.

[0027] DESCRIPTION OF REFERENCE NUMERALS

[0028] 2A, 2C, 2E lens barrels

[0029] 2a first barrel portion

[0030] 2b step portion

[0031] 2c, 2cE second barrel portions

[0032] 3 objective-side sealing member

[0033] 4 sealing member

[0034] 5, 5D retainers (front press rings)

[0035] 6 filter

[0036] 8 heater

[0037] 8w length of the heater in the optical axis direction (heater thickness)

[0038] 25 crimping structure portion (front press ring, thermal crimping)

[0039] 100 Camera module

[0040] 101A, 101B, 101C, 101D, 101E lens units

[0041] 103 Imaging element

[0042] L1 lens (first lens)

[0043] L2 lens (second lens)

[0044] L3, L4, L5, L6 lenses

[0045] S1, S2, S3, S4, S5 spacers

[0046] S1bA Second lens abutment area

[0047] S1bB Step portion relative area

[0048] Dw Spacing distance (specified distance) between the step portion relative area of the spacer and the step portion of the lens barrel Detailed implementation mode

[0050] [Configuration of the lens unit]

[0051] [Configuration of the lens unit]

[0052] Hereinafter, an embodiment of the present invention will be described in detail. Figure 1 It is a cross-sectional view schematically showing the configuration of the lens unit according to Embodiment 1 of the present invention. In addition, details of the optical systems of the respective lenses provided in the lens unit are omitted in the figure.

[0053] As Figure 1 shown, the lens unit 101A includes at least lenses L1 to L6, a lens barrel 2A, spacers S1 to S5, a sealing member 4, a retainer 5, a filter 6, and a heater 8. The lens unit 101A is, for example, an in-vehicle lens unit mounted on an in-vehicle camera.

[0054] [Lens barrel]

[0055] The lens barrel 2A is configured to integrally have a first barrel portion 2a, a step portion 2b, and a second barrel portion 2c in order from the eyepiece side. The first barrel portion 2a is a portion closer to the eyepiece side than the step portion 2b. The step portion 2b is a portion that expands outward in a direction intersecting the axis of the first barrel portion 2a (for example, a direction perpendicular to the axis). The second barrel portion 2c is a portion continuous from the step portion 2b toward the objective side and has a diameter larger than that of the first barrel portion 2a.

[0056] The lens barrel 2A holds the lenses L1 to L6 in the barrel in sequence. The lens L1 is the lens closest to the objective lens side (the first lens). The lens L1 is held in the second barrel portion 2c. Hereinafter, the lenses L2 to L6 are held in the first barrel portion 2a in sequence from the objective lens side to the eyepiece lens side. The outer peripheral portion of the lens L2 on the objective lens side protrudes more toward the objective lens side than the step portion 2b.

[0057] In addition, Figure 1 The optical axes X of the lenses L1 to L6 are shown. In addition, the optical axis X is on the same line as the axis of the lens barrel 2A.

[0058] The lens barrel 2A is made of resin, for example. The resin is a resin that can be insert-molded with a conductive member (such as a wiring), for example. In this case, one or more resins can be used. Examples of such resin materials include super engineering plastics such as Renee (registered trademark) and polyphenylene sulfide (PPS). In addition to the resin material, additives such as a plasticizer, an ultraviolet absorber, a light stabilizer, and a filler can be contained. As described above, when the lens unit 101A is an in-vehicle lens unit, the lens unit 101A is used for applications related to passenger safety and comfort during vehicle operation, such as autonomous driving, assisted driving, and surrounding monitoring. Therefore, the in-vehicle lens unit is required to have high reliability. Thus, a super engineering plastic can be used to manufacture the lens barrel 2A, which has high heat resistance, durability, and dimensional stability, and is cheaper in manufacturing cost than metal parts and suitable for mass production.

[0059] In addition, the lens barrel 2A is not limited to being made of resin and can also be made of metal.

[0060] A lens reference surface is provided on the eyepiece lens side of the first barrel portion 2a (lens barrel 2A), and the lenses L1 to L6 and the filter 6 are held.

[0061] <Lens>

[0062] The lenses L1 to L6 are held in the above-mentioned portion of the lens barrel 2A. The lens L1 is the lens closest to the objective lens side (the first lens). The lens L2 (the second lens) is the lens on the eyepiece lens side of the lens L1. In addition, in the present embodiment, six lenses are provided, but there is no particular limitation on the number of lenses provided in the lens unit.

[0063] The materials of the lenses L1 to L6 have sufficient light transmittance and can be one kind or more than one kind. The materials of the lenses L1 to L6 can be appropriately determined from the viewpoints of low cost and suitability for mass production. Examples of the materials of the lenses L1 to L6 include glass, acrylic resin, polystyrene resin, polycarbonate resin, and polyolefin.

[0064] Here, Figure 1The lower side shows an enlarged cross-sectional view centered on the lenses L1 and L2. As Figure 1 shown on the lower side, on the eyepiece side surface of the lens L1, a chamfered eyepiece side stepped portion L1c is provided over the entire periphery. The sealing member 4 is inserted into the eyepiece side stepped portion L1c. The sealing member 4 will be described later.

[0065] <Holder>

[0066] The holder 5 (front retaining ring) abuts against the peripheral portion of the lens L1 from the objective side and is pressed in the axial direction of the lens barrel 2A to fix the lenses L1 to L6 and the filter 6 relative to the lens barrel 2A.

[0067] The holder is configured such that an opening 5k centered on the optical axis X is provided on the objective side of the holder 5, and light can enter the objective side optical surface of the lens L1 through the opening 5k.

[0068] For example, the holder 5 has a first threaded portion on its inner peripheral surface, and is fixed (threaded connection) to the lens barrel 2A by screwing the first threaded portion with a second threaded portion formed on the outer peripheral surface of the objective side end of the lens barrel 2A. The holder 5 presses and closely adheres to the peripheral portion on the objective side of the lens L1.

[0069] In other words, the holder 5 is a lens cover that presses the lens L1 in the axial direction. The holder 5 is made of resin or metal.

[0070] <Sealing member>

[0071] The sealing member 4 is a sealing member arranged over the entire periphery of the lens L1 on the eyepiece side. The sealing member 4 is located at the corner of the stepped portion 2b and the second cylinder portion 2c in the lens barrel 2A. The sealing member 4 closely adheres to the inner peripheral surface of the second cylinder portion 2c, the surface of the stepped portion 2b, and the eyepiece side peripheral portion of the lens L1 over the entire periphery, and seals the lens barrel 2A and the lens L1 in a liquid-tight manner.

[0072] The sealing member 4 is an annular structure centered on the optical axis X and is arranged along the periphery of the lens L1 (first lens). The sealing member 4 is squeezed flat between the stepped portion 2b and the eyepiece side of the lens L1 by fixing the holder 5 to the lens barrel 2A. As a result, the sealing member 4 closely adheres to the inner peripheral surface of the second cylinder portion 2c, the surface of the stepped portion 2b, and the eyepiece side peripheral portion of the lens L1 over the entire periphery, and seals the lens barrel 2A side and the optical axis X side in a liquid-tight manner with the sealing member 4 as the boundary. The sealing member 4 can be composed of an O-ring.

[0073] The material of the sealing member 4 is not particularly limited, and EPDM (ethylene propylene rubber), NBR (nitrile rubber), VMQ (silicone rubber), etc. can be used. Among them, from the viewpoints of the use temperature range, weather resistance, water resistance, and chemical resistance, EPDM is preferably used.

[0074] <Spacer>

[0075] The spacers S1 to S5 are annular structures arranged between adjacent lenses. Specifically, a spacer S1 is arranged between the lens L1 (first lens) and the lens L2. In addition, a spacer S2 is arranged between the lens L2 and the lens L3. In addition, a spacer S3 is arranged between the lens L3 and the lens L4. In addition, a spacer S4 is arranged between the lens L5 and the lens L6. In addition, a spacer S5 is arranged between the lens L6 and the filter 6. The spacers S1 to S5 can be realized using known spacer materials.

[0076] As Figure 1 As shown below, the spacer S1 between the lens L1 (first lens) and the lens L2 contacts the lens L1 on the first surface S1a on the objective side. In addition, the spacer S1 contacts the lens L2 on the second surface S1b on the eyepiece side. In other words, in the state where the holder 5 is fixed to the lens barrel 2A, the spacer S1 is held between the lens L1 and the lens L2.

[0077] The second surface S1b of the spacer S1 includes: a second lens contact region S1bA that contacts the lens L2, and a step portion facing region S1bB (second lens non-contact region) that does not contact the lens L2. The step portion facing region S1bB extends from the end of the second lens contact region S1bA toward the step portion 2b and faces the step portion 2b in the optical axis direction. In other words, the second surface S1b of the spacer S1 has an annular second lens contact region S1bA along the periphery of the optical axis X near the optical axis X, and an annular step portion facing region S1bB on the outer peripheral side of the annular second lens contact region S1bA.

[0078] The step portion facing region S1bB is spaced apart from the step portion 2b by a predetermined distance ( Figure 1 the Dw shown below). More specifically, in the state where the holder 5 is fixed to the lens barrel 2A, there is a gap of the predetermined distance Dw between the step portion facing region S1bB and the step portion 2b.

[0079] As the material of the spacer S1, a known spacer can be used as long as it has thermal conductivity. For example, it is preferably made of metal, and specifically, aluminum, brass, etc. can be used. Since these materials have high thermal conductivity, the temperature of the heater 8 can be quickly transferred to the lens. In addition, the other spacers S2 to S5 may be made of the same material as the spacer S1, but may also be made of, for example, resin or the like.

[0080] For example, the first surface S1a of the spacer S1 can be processed to prevent light reflection.

[0081] <Heater>

[0082] The heater 8 is, for example, an annular heater and is fixed to the step portion opposing region S1bB of the second surface S1b of the spacer S1. The heater 8 fixed to the step portion opposing region S1bB is disposed opposite to the step portion 2b. The heater 8 is fixed to the step portion opposing region S1bB using an adhesive, for example.

[0083] The heater 8 heats up the lens L1 via the spacer S1. That is, the heat generated by the heater 8 is transferred to the spacer S1 via the step portion opposing region S1bB, and further transferred from the first surface S1a of the spacer S1 to the lens L1 in contact with the first surface S1a. By heating up the lens L1 in this way, even when the external environmental temperature of the lens unit 101A is low (for example, in a cold region), for example, the ice adhering to the lens surface can be melted when parking, and thus a highly reliable lens unit can be realized.

[0084] In a state where the heater 8 is fixed to the step portion opposing region S1bB and the holder 5 is fixed to the lens barrel 2A, the length of the heater 8 in the optical axis direction (the thickness of the heater 8) ( Figure 1 8w shown below) is a heater having a size equal to or less than the specified distance Dw. A member having heat insulation or elasticity can be disposed between the heater 8 and the step portion 2b.

[0085] With this configuration, as Figure 1 shown below, the force for fastening the lens L1 (the force for fastening it to the specified position of the lens barrel 2A) generated when the holder 5 is fixed to the lens barrel 2A is not transferred to the heater 8. Therefore, a failure of the heater 8 due to the fastening force does not occur. In addition, the fastening force of the lens L1 and the fastening force applied to the lens L1, the spacer S1, and the lens L2 when the lens L1 is fastened are Figure 1 schematically shown by the arrows below. As shown by the arrows, when the lens L1 is fastened, even if the lens L1 presses the spacer S1 toward the eyepiece side, the pressing force thereof is only transferred to the lens L2 via the spacer S1 and does not reach the heater 8.

[0086] In addition, in other words, it is configured such that a heater 8 having a size that can be accommodated in the space surrounded by the protruding outer peripheral portion on the objective side of the lens L2, the second surface S1b of the spacer S1 (the stepped portion relative region S1bB), the second cylinder portion 2c, and the stepped portion 2b is provided. It can be said that the heater 8 is disposed outside the outer diameter of the lens L2.

[0087] Furthermore, if the heater 8 is designed to be installed at the above position, compared with the method of disposing the heater between the lens closest to the objective side and the lens on the eyepiece side of that lens, only the spacer is disposed between the lenses. Therefore, according to the present embodiment, there is also an advantage that the optical performance is not adversely affected by the dimensional accuracy of the heater. In short, in the case of the comparison method, that is, when the heater is disposed between the lenses, if the dimensional accuracy of the heater is poor, there is a risk that the interval between the lenses may be different from the design, or the optical axes of the lenses may not be aligned (eccentric). On the other hand, according to the configuration of the present embodiment, such a risk does not exist, and a high-precision lens unit can be achieved.

[0088] In this way, according to the configuration of the present embodiment, the optical performance is not adversely affected by the dimensional accuracy of the heater, and the failure of the heater 8 due to the fastening force does not occur. Therefore, favorable effects can be obtained in terms of cost and quality. In addition, the components for supplying power to the heater 8 and their arrangements are not particularly limited.

[0089] As Figure 1 shown, the size (surface area) of the heater 8 is smaller than that of the spacer S1, and the contact area between the spacer S1 and the lens L1 is larger than the case where the small heater 8 is in direct contact with the lens L1. Therefore, according to Figure 1 this method, compared with the case where the small heater 8 is in direct contact with the lens L1, the heating area of the lens L1 becomes larger, and the lens L1 can be heated evenly.

[0090] In addition, the heater 8 is not limited to a heater having an annular shape when viewed from the optical axis direction, and may also be an arc-shaped heater. As an example, it may be a method of arranging a plurality of arc-shaped heaters 8 side by side along the annular stepped portion 2b. Or, not limited to having an arc-shaped heater, it may also be a rectangular heater accommodated within the width of the stepped portion 2b, as long as it does not affect the optical performance of the lens L1 and other components.

[0091] <Filter>

[0092] The filter 6 is disposed on the eyepiece side of the lens unit 101A. As the filter 6, a known filter having optical characteristics can be used. For example, an IR cut filter, a polarization filter, an ND filter, a band-pass filter, etc. can be adopted as the filter 6.

[0093] [Manufacture of Lens Unit]

[0094] As a method of assembling the lens unit 101A, prepare the lens barrel 2A, dispose the heater 8 from the opening on the objective side of the lens barrel 2A at the stepped portion 2b, and then insert the other components into the lens barrel 2A from the opening on the objective side of the lens barrel 2A. That is, after inserting the filter 6 and disposing it on the eyepiece side, the spacers S5 to S1 and the lenses L6 to L1 are alternately inserted in the order shown Figure 1 In addition, before disposing the lens L1, the sealing member 4 is disposed on the objective side of the spacer S1. Next, the retainer 5 is fixed to the lens barrel 2A. The lens unit 101A can be assembled by the above method.

[0095] In addition, the assembling method is not limited to this. For example, the method can be to pre-fix the heater 8 on the second surface S1b of the spacer S1 and dispose the spacer S1 on the objective side of the lens L2.

[0096] [Configuration of Camera Module]

[0097] Figure 2 is a diagram schematically showing the configuration of the camera module according to the present embodiment. As shown Figure 2 in, the camera module 100 includes a lens unit 101A, a housing 102, and an imaging element 103. The camera module 100 is used for an in-vehicle camera.

[0098] The housing 102 is a housing and has an opening portion into which the lens barrel 2A of the lens unit 101A is inserted. The lens unit 101A is inserted into this opening portion and is fixed to the housing 102 in a state where the stepped portion of the lens barrel 2A abuts against the opening edge portion of the housing 102.

[0099] The imaging element 103 is fixed at a position centered on the axis of the lens barrel 2A at the bottom of the housing 102. The imaging element 103 is an imaging sensor, and examples thereof include a complementary metal oxide semiconductor (CMOS) camera and a charge coupled device (CCD) camera.

[0100] In addition, the camera module 100 further includes various components for operating the lens unit 101A. For example, the camera module 100 can further include wirings and power supplies (not shown).

[0101] (Modification Example)

[0102] In the above-described embodiment, as Figure 1 shown on the lower side, the spacer S1 is configured such that the first surface S1a and the second surface S1b are flat from the end portion close to the optical axis X to the end portion close to the lens barrel 2A. However, it is not limited to such a flat manner. For example, the spacer S1 may be provided with a concave portion along the shape of the heater 8 on the second surface S1b.

[0103] 〔Embodiment 2〕

[0104] Another embodiment of the present invention will be described below. In addition, for ease of explanation, components having the same functions as those already described in the above-described embodiment are given the same reference numerals, and their descriptions will not be repeated.

[0105] Figure 3 FIG. is a cross-sectional view schematically showing the configuration of the lens unit 101B according to Embodiment 2 of the present invention. In the lens unit 101A of Embodiment 1, on the eyepiece side of the lens L1 (first lens), a chamfered eyepiece-side stepped portion L1c is provided over the entire periphery, and the sealing member 4 is fitted into the eyepiece-side stepped portion L1c. In contrast, in the lens unit 101B of the present embodiment, there is no eyepiece-side stepped portion L1c on the eyepiece side of the lens L1 (first lens), nor is there a sealing member 4.

[0106] In addition, although Embodiment 1 and the present embodiment differ in the number of lens elements and the total number of spacers, the relationship between the lens L1 closest to the objective side, the lens L2 on the eyepiece side thereof, the spacer S1 sandwiched between the lens L1 and the lens L2, the heater 8 fixed to the spacer S1, and the lens barrel 2A and the stepped portion 2b is the same as that described in Embodiment 1. Therefore, similar to the lens unit 101A of Embodiment 1, in the lens unit 101B, the optical performance is not adversely affected by the dimensional accuracy of the heater, and the heater 8 does not malfunction due to the fastening force. Therefore, advantageous effects can be obtained in terms of cost and quality. In addition, in Figure 3 for ease of explanation, the illustration of the Figure 1 filter 6 shown is omitted.

[0107] 〔Embodiment 3〕

[0108] Another embodiment of the present invention will be described below. In addition, for ease of explanation, components having the same functions as those already described in the above-described embodiment are given the same reference numerals, and their descriptions will not be repeated.

[0109] Figure 4 FIG. is a cross-sectional view schematically showing the configuration of the lens unit 101C according to Embodiment 3 of the present invention. As Figure 4As shown, the lens barrel 2C of the lens unit 101C has a crimping structure portion 25 at the objective lens side opening portion, and each component arranged within the lens barrel 2C is fixed to the inside of the lens barrel 2C through the crimping structure portion 25. Therefore, the lens unit 101C is not equipped with the retainer 5 that the lens unit 101A of Embodiment 1 has.

[0110] When various components arranged within the lens barrel 2C are inserted into the lens barrel 2C from the objective lens side opening portion, the crimping structure portion 25 is in a state of standing upright toward the objective lens side. After inserting the various components from the objective lens side opening portion into the lens barrel, as Figure 4 shown, the crimping structure portion 25 that stands upright toward the objective lens side becomes a state of bending toward the optical axis side, thereby fixing the lens and the like.

[0111] In addition, although Embodiment 1 and this embodiment differ in the number of lens elements and the total number of spacers, the relationship between the lens L1 closest to the objective lens side, the lens L2 on its eyepiece side, the spacer S1 sandwiched between the lens L1 and the lens L2, the heater 8 fixed to the spacer S1, and the lens barrel 2C and the stepped portion 2b is the same as that described in Embodiment 1. Therefore, similar to the lens unit 101A of Embodiment 1, in the lens unit 101C, the optical performance is not adversely affected by the dimensional accuracy of the heater, and the heater 8 does not malfunction due to the fastening force. Thus, favorable effects can be obtained in terms of cost and quality. Note that in Figure 4 , for ease of explanation, the illustration of the Figure 1 shown filter 6 is omitted.

[0112] 〔Embodiment 4〕

[0113] Another embodiment of the present invention will be described below. In addition, for ease of explanation, components having the same functions as those already described in the above embodiments are given the same reference numerals, and their descriptions will not be repeated.

[0114] Figure 5 is a cross-sectional view schematically showing the configuration of the lens unit 101D according to Embodiment 4 of the present invention. As Figure 5 shown, in the lens unit 101D, a chamfered objective lens side stepped portion L1d is provided at the outer peripheral portion of the objective lens side surface L1a of the lens L1. On the other hand, there is no chamfered portion at the outer peripheral portion of the eyepiece side surface L1b of the lens L1. In this regard, the lens unit 101D is different from Embodiment 1 in which an eyepiece side stepped portion L1c is provided at the outer peripheral portion of the eyepiece side surface L1b of the lens L1. In addition, as Figure 5 shown, the lens unit 101D is different from Embodiment 1 in that an objective lens side seal member 3 is arranged at the objective lens side stepped portion L1d.

[0115] In addition, as Figure 5 shown, in the lens unit 101D, in the region of the retainer 5D on the lens L1 side, it includes a lens contact portion 5a that contacts the object-side surface L1a of the lens L1, and a seal member contact portion 5b that contacts the objective-side seal member 3. Such a way of the retainer is also different from that of the retainer in Embodiment 1. In addition, in Figure 5 , for ease of explanation, the illustration of the filter 6 shown in Figure 1 is omitted.

[0116] In addition, although the number of lenses and the total number of spacers in Embodiment 1 and this embodiment are different, the relationship between the lens L1 closest to the objective side, its eyepiece-side lens L2, the spacer S1 between them, the heater 8 fixed on the spacer S1, and the relationship between the lens barrel 2A and the stepped portion 2b is the same as that described in Embodiment 1. Therefore, similar to the lens unit 101A in Embodiment 1, in the lens unit 101D, the optical performance will not be adversely affected due to the dimensional accuracy of the heater, and the heater 8 will not malfunction due to the fastening force. Therefore, favorable effects can be obtained in terms of cost and quality.

[0117] 〔Embodiment 5〕

[0118] Another embodiment of the present invention will be described below. In addition, for ease of explanation, components having the same functions as those already described in the above embodiments are given the same reference numerals, and their descriptions will not be repeated.

[0119] Figure 6 is a cross-sectional view schematically showing the configuration of the lens unit 101E according to Embodiment 5 of the present invention. As Figure 6 shown, the difference between the lens unit 101E and that in Embodiment 1 is that there is a stepped portion 2d in the middle part of the second barrel portion 2cE of the objective-side opening of the lens barrel 2E of the lens unit 101E, while there is no such stepped portion in the second barrel portion 2c in Embodiment 1.

[0120] The second barrel portion 2cE includes: a lower barrel portion that is continuous with the stepped portion 2b; a stepped portion 2d that is continuous with the lower barrel portion and extends outward along a direction (for example, a direction perpendicular to this axis) intersecting the optical axis X; and an upper barrel portion that is continuous with the stepped portion 2d and is located at the objective-side opening of the lens barrel 2E.

[0121] In addition, the seal member 4 with a stepped portion L1c on the eyepiece side embedded in the lens unit 101E is closely attached between the upper barrel portion, the stepped portion 2d, and the stepped portion L1c on the eyepiece side, and is sealed in a liquid-tight manner.

[0122] The outer peripheral edge of the spacer S1 is in contact with the circumferential surface of the lower cylindrical portion of the second cylindrical portion 2cE, or there is a minute gap therebetween.

[0123] Although Embodiment 1 and the present embodiment differ in the number of lens elements and the total number of spacers, the relationship among the lens L1 closest to the objective lens side, the lens L2 on the eyepiece side thereof, the spacer S1 sandwiched between the lenses L1 and L2, the heater 8 fixed to the spacer S1, and between the lens barrel 2E and the stepped portion 2b is the same as that described in Embodiment 1. Therefore, similar to the lens unit 101A of Embodiment 1, in the lens unit 101E, adverse effects on the optical performance due to the dimensional accuracy of the heater will not occur, and failures of the heater 8 due to the fastening force will not occur. Thus, advantageous effects can be obtained in terms of cost and quality. In addition, in Figure 6 For ease of explanation, Figure 1 the illustration of the filter 6 shown in

[0124] 〔Embodiment 6〕

[0125] Each of the above-described embodiments is a lens unit equipped with a lens barrel 2A having a stepped portion 2b, for example, as shown in Figure 1 . However, the present invention is not limited thereto. For example, in the present invention, the lens (first lens) closest to the objective lens side and the lens (second lens) on the eyepiece side of the lens may have the same diameter, and the inner diameter of the lens barrel may be uniform in the region where these lenses (first lens and second lens) are held. Even in this case, as long as it is the following manner: the portion near the inner circumferential surface of the lens barrel on the eyepiece side of the surface of the spacer (corresponding to the spacer S1 in the above-described embodiments) held by these lenses (first lens and second lens) is spaced apart from the lens (second lens) on the eyepiece side, the same effects as those achieved in the above-described embodiments can be obtained by disposing the heater in this spaced portion.

[0126] In addition, as a specific example of the spacing manner, there can be the following example, that is, the portion near the inner circumferential surface of the lens barrel on the eyepiece side of the surface of the spacer (corresponding to the spacer S1 in the above-described embodiments) is recessed toward the objective lens side. As another specific example, there can be the following example, that is, the outer peripheral portion on the objective lens side of the surface of the lens (second lens) on the eyepiece side is recessed toward the eyepiece side. Based on these specific examples, a spaced portion can be provided between the portion near the inner circumferential surface of the lens barrel on the eyepiece side of the surface of the spacer (corresponding to the spacer S1 in the above-described embodiments) and the lens (second lens) on the eyepiece side. The heater can be disposed in this portion.

[0127] [Summary]

[0128] As can be clearly seen from the above description, the lens unit of the first aspect of the present invention includes: a first lens located closest to the objective lens side; a second lens located on the eyepiece side of the first lens; a spacer located between the first lens and the second lens, contacting the first lens on the first surface on the objective lens side and contacting the second lens on the second surface on the eyepiece side; and a lens barrel that houses at least the first lens, the second lens, and the spacer. Among them, the spacer includes a second lens contact area that contacts the second lens on the second surface, and a second lens non-contact area that is arranged closer to the outer diameter direction than the second lens contact area and does not contact the second lens. A heater is installed in the second lens non-contact area of the lens unit. According to the first aspect, the force for fastening the first lens (the force for fastening it to a specified position of the lens barrel) is not transmitted to the heater, so that a failure of the heater due to the fastening force does not occur. In addition, the optical performance is not adversely affected by the dimensional accuracy of the heater. These factors enable the lens unit to have advantages in terms of cost and quality.

[0129] The lens unit of the second aspect of the present invention is based on the first aspect, wherein the lens barrel has: a first barrel portion that holds the second lens; a second barrel portion that is closer to the objective lens side than the first barrel portion and has a larger diameter than the first barrel portion; and a step portion that is a portion between the first barrel portion and the second barrel portion and extends outward in a direction crossing the axis of the first barrel portion. Among them, the second lens non-contact area of the spacer is a step portion relative area that is opposite to the step portion in the optical axis direction and is spaced a specified distance from the step portion in the optical axis direction. The heater can also be installed in the step portion relative area and has a length in the optical axis direction that is equal to or less than the specified distance. According to the first aspect, a heater with a length in the optical axis direction that is equal to or less than the specified distance is installed in the step portion relative area that is spaced a specified distance from the step portion in the optical axis direction. Therefore, the force for fastening the first lens (the force for fastening it to a specified position of the lens barrel) is not transmitted to the heater, so that a failure of the heater due to the fastening force does not occur. In addition, the optical performance is not adversely affected by the dimensional accuracy of the heater. These factors enable the lens unit to have advantages in terms of cost and quality.

[0130] The lens unit of the third aspect of the present invention is based on the first aspect or the second aspect, and the heater is arranged outside the outer diameter of the second lens. According to the third aspect, the heater is housed in a gap that is provided outside the outer diameter of the second lens and is surrounded by the step portion relative area of the second surface of the spacer, the second barrel portion, and the step portion.

[0131] In the lens unit according to the fourth aspect of the present invention, in any one of the first to third aspects, the spacer may be made of metal. According to the fourth aspect, the spacer has good thermal conductivity, and the heat of the heater disposed on the second surface of the spacer can be well transferred to the first lens in contact with the first surface of the spacer, thereby raising the temperature of the first lens.

[0132] In the lens unit according to the fifth aspect of the present invention, in any one of the first to fourth aspects, there is further provided: a sealing member that is disposed on the outer side of the optical surface of the first lens, on at least one of the objective side and the eyepiece side, and extends over the entire circumference of the first lens. According to the fifth aspect, even if water enters the lens barrel from the object side of the lens unit, the sealing member can prevent the water from entering the eyepiece side of the first lens.

[0133] In the lens unit according to the sixth aspect of the present invention, in any one of the first to fifth aspects, the first lens is fixed to the lens barrel by a screw connection of a front retaining ring or is fixed to the lens barrel by a thermal press fit provided on the lens barrel.

[0134] The camera module according to the seventh aspect of the present invention includes: the lens unit according to any one of the first to sixth aspects; and an imaging element. According to the sixth aspect, a vehicle-mounted camera with high reliability can be provided.

[0135] According to such a configuration, a lens unit suitable for a vehicle-mounted camera can be provided. Thus, it is expected to establish an environment that promotes automation such as autonomous driving of automobiles. Therefore, it is expected that the present invention will contribute to the achievement of the Sustainable Development Goals (SDGs) regarding the expansion of technological innovation and the promotion of sustainable industrialization.

[0136] The present invention is not limited to the above-described embodiments, and various changes are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

Claims

1. A lens unit comprising: A first lens, which is located closest to the objective lens; a second lens located on the eyepiece side of the first lens; a spacer located between the first lens and the second lens, the spacer being in contact with the first lens at a first surface on the objective lens side and in contact with the second lens at a second surface on the eyepiece side; and A lens barrel that accommodates at least the first lens, the second lens and the spacer, wherein: The spacer includes, on the second surface, a second lens contact region that contacts the second lens, and a second lens non-contact region that is arranged closer to the outer diameter direction than the second lens contact region and does not contact the second lens. The lens unit has a heater installed in a non-contact region of the second lens.

2. The lens unit according to claim 1, wherein: The lens barrel has: a first barrel portion that holds the second lens; a second barrel portion, which is closer to the objective lens side than the first barrel portion and has a larger diameter than the first barrel portion; as well as The step portion is a portion between the first barrel portion and the second barrel portion and extending outward in a direction intersecting the axis of the first barrel portion, wherein: The second lens non-contact region of the spacer is a step portion-opposing region that is opposed to the step portion in the optical axis direction and is spaced a predetermined distance from the step portion in the optical axis direction. The heater is installed in the region facing the step portion, and has a length along the optical axis that is less than the predetermined distance.

3. The lens unit according to claim 1, wherein: The heater is arranged outside the outer diameter of the second lens.

4. The lens unit according to claim 1, wherein: The spacer is made of metal.

5. The lens unit according to claim 1, further comprising: A sealing member is disposed outside the optical surface of the first lens, on at least one of the objective lens side and the eyepiece side, over the entire periphery of the first lens.

6. The lens unit according to claim 1, wherein: The first lens is fixed to the lens barrel by a threaded connection of a front pressure ring, or is fixed to the lens barrel by a thermal compression connection provided on the lens barrel.

7. A camera module, comprising: The lens unit according to any one of claims 1 to 6; as well as Camera element.

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