Plastic lenses and bonded lenses equipped therewith, camera modules, imaging devices, in-vehicle systems, mobile bodies

Abstract

We provide plastic lenses with excellent optical properties and suppressed weld lines. [Solution] A plastic lens having a concave first surface, a concave second surface on the opposite side of the first surface, and a side gate mark between the first surface and the second surface, wherein the thickness along the optical axis between the central part of the first lens through which the optical axis of the first surface passes and the central part of the second lens through which the optical axis of the second surface passes is thinner than the thickness in the direction parallel to the optical axis between the outer periphery of the first lens outside the central part of the first lens and the outer periphery of the second lens outside the central part of the second lens, and the diameter of the first optical functional surface of the central part of the first lens is smaller than the diameter of the second optical functional surface of the central part of the second lens.

Description

Technical Field

[0001] The present invention relates to a plastic lens having optical characteristics, a cemented lens including the same, a camera module, an imaging device, an in-vehicle system, and a moving body.

Background Art

[0002] In recent years, plastic lenses are frequently used in various imaging lens systems of imaging devices because they are easy to process, excellent in cost reduction, and lightweight. Along with this, many plastic lenses and their manufacturing methods have been proposed. Plastic lenses are manufactured by an injection molding method. The injection molding method involves manufacturing a mold for forming a lens surface, injecting a thermoplastic resin (hereinafter referred to as resin) from a side gate of a cavity formed by this mold, and cooling and solidifying it to form a plastic lens. Patent Document 1 describes a plastic lens formed of resin.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when molding a plastic lens by an injection molding method, it is necessary to consider the direction of the resin flowing in the cavity. In the central side portion where the central portion of the lens is formed, the resin that has melted later flows more slowly than the portion formed closer to the center of the outer peripheral portion of the lens. Also, in the portion closer to the outer periphery of the outer peripheral portion of the lens, the resin that has melted later flows more slowly than the portion closer to the center of the outer peripheral portion of the lens.

[0005] Therefore, weld lines, which are traces of the merging of resin that flowed first and resin that flowed later, or of merging from different directions, may remain on the opposite side of the side gate mark. These weld lines are more likely to occur when molding concave plastic lenses where the thickness of the central part is thinner than the thickness of the outer periphery.

[0006] If weld lines remain, plastic lenses will experience a degradation in optical performance. For high-resolution image sensors, the presence of weld lines in plastic lenses is problematic as it degrades the image quality.

[0007] The present invention has been made in view of the above, and provides a plastic lens with excellent optical properties in which weld lines are suppressed. [Means for solving the problem]

[0008] A plastic lens having a concave first surface, a concave second surface on the opposite side of the first surface, and a side gate mark between the first and second surfaces, wherein the thickness along the optical axis between the central part of the first lens through which the optical axis of the first surface passes and the central part of the second lens through which the optical axis of the second surface passes is thinner than the thickness in the direction parallel to the optical axis between the outer periphery of the first lens outside the central part of the first lens and the outer periphery of the second lens outside the central part of the second lens, and the diameter of the first optical functional surface of the central part of the first lens is smaller than the diameter of the second optical functional surface of the central part of the second lens. [Effects of the Invention]

[0009] This invention can provide a plastic lens with excellent optical properties and suppressed weld lines. [Brief explanation of the drawing]

[0010] [Figure 1] This is a plan view of the plastic lens according to Example 1. [Figure 2] This is a cross-sectional view of a plastic lens according to Example 1. [Figure 3]This is a diagram showing the cavity for molding the plastic lens according to Example 1. [Figure 4] This is a schematic diagram showing the flow state of the resin in the cavity used to mold the plastic lens according to Example 1. [Figure 5] This is a plan view of the plastic lens according to Example 2. [Figure 6] This is a cross-sectional view of the plastic lens according to Example 2. [Figure 7] This is a schematic diagram showing the flow state of the resin in the cavity used to mold the plastic lens according to Example 2. [Figure 8] This is a cross-sectional view of the lens according to Example 3. [Figure 9] This is a cross-sectional view showing the lens configuration of an imaging lens system that includes plastic lenses. [Figure 10] This is a diagram illustrating the configuration of an imaging device equipped with an imaging lens system. [Figure 11] This is a schematic diagram of a vehicle equipped with an imaging device. [Figure 12] This is a diagram showing the configuration of a vehicle equipped with an imaging device. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings and other figures. In the drawings and descriptions of this embodiment, functionally identical elements may be indicated by the same number. The following description shows embodiments in accordance with the principle, but these are for the purpose of understanding this embodiment and are not to be used to interpret this embodiment restrictively. The description of this embodiment is merely a typical example and does not limit the scope of the claims or applications in any way.

[0012] Although this embodiment has been described in sufficient detail for those skilled in the art to implement, it is important to understand that other forms are possible, and that the configuration and structure can be modified and various elements replaced without departing from the scope and spirit of the technical idea. Therefore, the following description should not be interpreted as limiting.

[0013] In addition, this embodiment can realize a highly reliable system particularly in a sensing system, aiming to construct a resilient infrastructure, promote inclusive and sustainable industrialization, and advance innovation. It targets "9. Build the foundation of industry and technological innovation" in the Sustainable Development Goals (SDGs) proposed by the United Nations, specifically "9.1: Develop high-quality, reliable, sustainable, and resilient infrastructure, including regional and cross-border infrastructure, to support economic development and human well-being with a focus on providing affordable and equitable access for all people." [Embodiment 1] Hereinafter, based on the embodiments of the present invention, the plastic lens according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an example of the first embodiment and also relates to Example 1. [Example 1] Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the plastic lens according to this invention will be described in detail. A concave plastic lens with a thinner central thickness than the outer peripheral thickness is formed by an injection molding method.

[0014] At this time, in the central side portion where the central portion of the lens in the cavity is formed, the resin that has melted later flows, which is slower than the portion formed closer to the center of the lens outer periphery. Also, in the portion of the lens outer periphery closer to the outer periphery, the resin that has melted later flows, which is slower than the portion closer to the center of the lens outer periphery.

[0015] Therefore, weld lines may remain in the plastic lens. To avoid this, the molding of the plastic lens is performed such that the resin flows at a uniform speed within the cavity.

[0016] Figure 1 is a plan view of a plastic lens. Figure 2 is a cross-sectional view along line AA in Figure 1. As shown in Figures 1 and 2, the plastic lens 400 has a concave first surface 410 and a concave second surface 420 that have optical functions for transmitting or refracting light rays, and an outer surface 430 that is connected to the outer periphery of the first surface 410 and also connected to the outer periphery of the second surface 420.

[0017] The central part 412 of the first surface 410, where the light ray enters, is the first lens center. The central part 422 of the second surface 420, opposite to the first surface 410, where the light ray exits, is the second lens center. The thickness of the lens center 412 and the lens center 422 along the optical axis O is thinner than the thickness of the outer lens periphery 411 of the first surface 410 and the outer lens periphery 421 of the second lens, which is outside the lens center 422, in a direction parallel to the optical axis O, and the thickness difference ratio is 3 or more.

[0018] Furthermore, the concave shape of the lens center portion 412 of the first surface 410 has a gentler curvature and a larger radius of curvature than the concave shape of the lens center portion 422 of the second surface 420. In addition, the lens center portion 412 of the first surface 410, which is the first optical functional surface diameter, has a smaller diameter than the lens center portion 422 of the second surface 420, which is the second optical functional surface diameter.

[0019] Furthermore, the plastic lens 400 has a side gate mark 431 in a portion of the outer surface 430 that is cut out between the flat surface of the outer periphery 411 of the first surface 410 and the flat surface of the outer periphery 421 of the second surface 420. That is, the side gate mark 431 is formed as a resin injection mark at the position where the side gate (see Figure 3) for injecting resin during lens molding is located. The distance from the optical axis O to the end of the side gate mark 431 is shorter than the distance from the optical axis O to the outer surface 430.

[0020] Figure 3 is a diagram showing the configuration of the cavity for molding the plastic lens 400. The cavities 1000 are stacked, and resin is injected into the cavity 1000 from the square-shaped side gate 1001. The injected resin forms the plastic lens 400 through inner wall flow, which flows along the peripheral portion 432 of the inner wall of the outer peripheral wall surface 1002 (see Figures 1 and 2), intermediate flow, which flows in the portion 433 on the optical axis O side of the inner wall flow, and axial flow, which flows near the optical axis O.

[0021] In the molding of the plastic lens 400 shown in Figure 1, the cavity shape is such that a concave shape is formed in the central part 412 of the first surface 410 through which the optical axis O passes, and a concave shape is formed in the central part 422 of the second surface 420 through which the optical axis O passes, as shown in Figure 2. As a result, the axial flow near the optical axis O becomes faster than when the cavity shape of the first surface 410 is formed as a planar or convex shape. That is, the axial flow flowing near the optical axis O and the intermediate flow on the outer circumference become closer to a uniform speed. As a result, this embodiment can provide a plastic lens with excellent optical properties in which weld lines are suppressed.

[0022] Figure 4 is a schematic diagram showing the flow state of the resin in the cavity 1000 where the plastic lens 400 is molded. The curves in Figure 4 indicate the leading edge position of the resin flow after a unit of time has elapsed.

[0023] The resin is injected from the side gate 1001 of the cavity 1000, forming the area around the side gate mark 431 of the plastic lens 400. The resin also flows to the left in Figure 4. Therefore, the axial flow, intermediate flow, and inner wall flow within the cavity 1000 are performed at a nearly uniform rate. As a result, the formation of weld lines 440 can be suppressed near the optical axis O of the plastic lens 400 and within the central part 412 of the lens, which is the optical functional surface diameter of the first surface 410.

[0024] For example, in Figure 2, light rays incident from above, which converge at the lens center 412 of the first surface 410, are diffused by the concave shape of the lens center 412. Here, the lens center 412 is designed so that the degree of diffusion of these light rays does not extend beyond the optical functional surface diameter of the lens center 412. The light rays then use the region of the optical functional surface where no weld lines 440 are generated at the lens center 422 of the second surface 420 that exits downward. As a result, this embodiment can provide a plastic lens with excellent optical properties in which weld lines are suppressed. [Example 2] Figure 5 is a plan view of the plastic lens 400 according to Embodiment 2. Figure 6 is a cross-sectional view along line AA in Figure 5. Line AA is a straight line passing through the optical axis center of the plastic lens. As shown in Figure 6, the plastic lens 400 has a concave first surface 410 and a concave second surface 420 having optical functions, and an outer peripheral surface 430 connected to the outer periphery of the first surface 410.

[0025] Furthermore, the second surface 420 has an outer lens portion 421 that connects to the outer edge of the lens central portion 422 on the outer side of the lens central portion 422. The outer lens portion 421 has an edge portion 423 having a downward planar shape that connects to the edge of the end of the lens central portion 422, and an inclined portion 424 that linearly connects the outer edge of the edge portion 423 to the end of the outer surface 430 on the second surface 420 side. The inclined portion 424 only needs to have an inclination in which the thickness decreases from the outer edge of the edge portion 423 to the end of the outer surface 430 on the second surface 420 side, and may also have a curved shape.

[0026] The thickness of the lens center portion 412 of the first surface 410 and the lens center portion 422 of the second surface 420 along the optical axis O is thinner than the thickness of the lens outer periphery portion 411 of the first surface 410 and the edge portion 423 of the lens outer periphery portion 421 in the direction parallel to the optical axis O.

[0027] Furthermore, the concave shape of the lens center portion 412 of the first surface 410 has a gentler curvature and a larger radius of curvature near the optical axis O than the concave shape of the lens center portion 422 of the second surface 420. In addition, the lens center portion 412, which is the optical functional surface diameter of the first surface 410, has a smaller diameter than the lens center portion 422, which is the optical functional surface diameter of the second surface 420. That is, the end of the lens center portion 412 is shorter from the optical axis O by a distance e than the end of the lens center portion 422.

[0028] Furthermore, the outer circumferential surface 430 has a side gate mark 431 formed at the location where the side gate for resin injection during lens molding is located. The distance from the optical axis O to the end of the side gate mark 431 is shorter than the distance from the optical axis O to the outer circumferential surface 430.

[0029] Furthermore, the length a of the inclined portion 424 in the direction of the optical axis O is longer than the length b of the outer surface 430 in the direction of the optical axis O. Also, the length a of the inclined portion 424 in the direction of the optical axis O is longer than the length c of the inclined portion 424 in the direction perpendicular to the optical axis O. The length d of the edge portion 423 in the direction perpendicular to the optical axis O is shorter than the length c of the inclined portion 424 in the direction perpendicular to the optical axis O. Also, the length d of the edge portion 423 in the direction perpendicular to the optical axis O is longer than the length e of the difference between the distance from the end of the lens central portion 422 to the optical axis O and the distance from the end of the lens central portion 412 to the optical axis O.

[0030] The length of the outer periphery 411 of the first lens on the first surface 410 is the sum of lengths c, d, and e, which is longer than the length of the outer periphery 421 of the second surface 420. The diameter of the plastic lens 400 is the sum of the outer periphery 411 and the central part 412 of the first surface 410, or the sum of the outer periphery 421 and the central part 422 of the second surface 420. Furthermore, the optical functional surface diameter of the first surface 410 is the diameter of the central part 412, and the optical functional surface diameter of the second surface 420 is the diameter of the central part 422.

[0031] The depth length f of the concave lens central portion 412 of the first surface 410 along the optical axis O is shorter than the depth length g of the concave lens central portion 422 of the second surface 420 along the optical axis O. Also, the depth length f is shorter than the length b of the outer peripheral surface 430 in the direction of the optical axis O. The depth length g is shorter than the length a of the inclined portion 424 in the direction of the optical axis O. Furthermore, the depth length f is shorter than the length of the side gate mark 431 formed on the outer peripheral surface 430 side in the direction of the optical axis O, and longer than the step length h between the plane of the outer peripheral portion 411 of the lens and the end of the side gate mark 431 in the direction of the optical axis O.

[0032] In the molding of the plastic lens 400 shown in Figure 5, the cavity shape, as shown in Figure 6, is such that a concave shape is formed at the center 412 of the first surface 410 and a concave shape is formed at the center 422 of the second surface 420. As a result, the axial flow near the optical axis O is faster than when the cavity shape of the first surface 410 is a planar or convex shape.

[0033] Furthermore, the flow along the peripheral portion 432 within the cavity is faster due to the cavity forming the inclined portion 424 than when the shape has a horizontal surface that does not correspond to the inclined portion 424.

[0034] In other words, even if the flow distance of the inner wall flow is longer than the flow distance of the intermediate flow, by creating a cavity that removes the thickness of the outer periphery of the lens outer edge 421, the inner wall flow becomes faster, and the inner wall flow and the intermediate flow inside it become closer to a uniform velocity. As a result, this embodiment can provide a plastic lens with excellent optical properties in which weld lines are suppressed.

[0035] Figure 7 is a schematic diagram showing the flow state of the resin in the cavity 1000 where the plastic lens 400 is molded. The curves in Figure 7 show the leading edge position of the resin flow after a unit of time has elapsed. The resin is injected from the side gate 1001 of the cavity 1000, and the area around the side gate mark 431 of the plastic lens 400 is molded first. After that, the resin flows to the left in Figure 7. The axial flow, the intermediate flow on the outer circumference of the axial flow, and the inner wall flow on the outer circumference of the intermediate flow converge in the central part 422 of the lens, which is the optical functional surface diameter of the second surface 420. No weld lines are generated at the confluence 441.

[0036] Therefore, within the cavity 1000, axial flow, intermediate flow, and inner wall flow occur at nearly uniform speeds. As a result, weld lines can be suppressed near the optical axis O of the plastic lens 400, within the lens center portion 412 which is the optical functional surface diameter of the first surface 410, and within the lens center portion 422 which is the optical functional surface diameter of the second surface 420.

[0037] For example, in Figure 6, light rays incident from above, which are concentrated or diffused at the lens center 412 of the first surface 410, are diffused by the concave lens center 412. The concave lens center 412 extends the degree of diffusion of these light rays beyond the optical functional surface diameter of the lens center 412. The light rays then utilize the entire area up to the optical functional surface diameter of the lens center 422 of the second surface 420 that exits downward. This embodiment allows us to provide a plastic lens with better optical properties and suppressed weld lines. [Example 3] Figure 8 is a partial cross-sectional view of the lens according to Example 3. Figure 8 shows a bonded lens formed by a plastic lens 400 and a lens 500. Specifically, the second surface 420 of the plastic lens 400 is bonded to the third surface 510 of the lens 500 by applying a synthetic resin adhesive or the like, thereby forming a bonded lens with the plastic lens 400 and the lens 500.

[0038] The first surface 410 of the plastic lens 400 has a concave shape. The second surface 420, opposite to the first surface 410, also has a concave shape. The plastic lens 400 is a negative lens, meaning it has a negative power and is thicker on the edges than on the center.

[0039] Lens 500 has a third surface 510 that has a convex shape and is opposite to the second surface 420 of the plastic lens 400. The fourth surface 520, opposite to the third surface 510, also has a convex shape. Lens 500 is a positive lens with positive power.

[0040] The plastic lens 400 has an outer peripheral surface 430 that connects to the outer circumference of the first surface 410. It also has an outer peripheral lens portion 421 that connects to the end of the lens central portion 422 on the outer side of the lens central portion 422 of the second surface 420. The outer peripheral lens portion 421 has a downward planar annular portion 425 that connects to the edge of the lens central portion 422, and a downward planar edge portion 423 that forms a step below the annular portion 425 on the side opposite to the first surface 410. In other words, the annular portion 425 has a shape in which a part of the edge portion 423 on the lens central portion 422 side in Figure 6 is cut out.

[0041] The outer periphery of the lens 421 has an inclined portion 424 that connects the outer end of the edge portion 423 to the end of the outer periphery surface 430 on the second surface 420 side. As a result, similar to Figure 6, this embodiment can provide a plastic lens with excellent optical properties in which weld lines are suppressed.

[0042] Furthermore, the plastic lens 400 can suppress weld lines by molding the inclined portion 424, and the optical functional surface diameter of the concave lens central portion 412 may be larger than the optical functional surface diameter of the concave lens central portion 422.

[0043] Furthermore, the outer peripheral portion 511 of the third surface 510 of the lens 500 has an annular portion 513 that contacts the edge portion 423 of the plastic lens 400, and an inclined portion 514 that contacts the inclined portion 424 of the plastic lens 400.

[0044] Thus, a gap exists between the annular portion 425 of the plastic lens 400 and the annular portion 513 of the lens 500, creating space for the adhesive to escape. As a result, when the lens center portion 422 of the second surface 420 of the plastic lens 400 and the lens center portion of the third surface 510 of the lens 500 are bonded together with adhesive, any excess adhesive is pushed into this gap, improving the bonding strength of the bonded lenses.

[0045] Furthermore, the rim portion 423 of the plastic lens 400 and the annular portion 513 of the lens 500, as well as the inclined portion 424 of the plastic lens 400 and the inclined portion 514 of the lens 500, ensure precise positioning of the lenses.

[0046] The bonded lens, consisting of plastic lens 400 and lens 500, is inserted into and installed in the barrel 1100, which is a cylindrical housing, when it is mounted from top to bottom in the drawing.

[0047] The outer peripheral portion 521 of the fourth surface 520 of lens 500 is positioned and supported by the support portion 1101 of barrel 1100 with respect to the optical axis O direction (insertion direction).

[0048] Furthermore, the diameter of the plastic lens 400 is larger than the diameter of the lens 500, and the outer circumferential surface 430 of the plastic lens 400 is positioned by the guide portion 1103 of the barrel 1100 and positioned and supported by the circumferential surface support portion 1102 of the barrel 1100 in a direction perpendicular to the optical axis O. [Differentiation] The present invention is not limited to the embodiments described above, but includes various other modifications. For example, the embodiments described above are explained in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described.

[0049] Furthermore, it is possible to replace parts of the configuration of one embodiment with parts of the configuration of another embodiment, and it is also possible to add parts of the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with parts of other configurations. [Embodiment 2] Figure 9 is a cross-sectional view showing the lens configuration of the imaging lens system 11 of a camera module 10 equipped with a plastic lens according to Embodiment 1. As shown in the figure, the camera module 10 according to the embodiment houses the imaging lens system 11 and the image sensor 12, etc., in a housing (not shown).

[0050] As shown in Figure 9, the imaging lens system 11 comprises a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5, and a sixth lens L6, in the order of the optical axis O direction from the object side to the image side.

[0051] Furthermore, the imaging lens system 11 includes a front lens group that determines the angle of view characteristics, etc., through the first lens L1, the second lens L2, and the third lens L3. In addition, the imaging lens system 11 has a front lens group and a rear lens group that contributes to brightness, light-gathering characteristics, etc., through the fourth lens L4, the fifth lens L5, and the sixth lens L6, flanking the optical aperture 1.

[0052] The first lens L1 has a lens surface S1 which is the object side of a spherical surface with positive curvature and a convex shape toward the object, and a lens surface S2 which is the image side of a spherical surface with positive curvature and a concave shape toward the image. The first lens L1 is a positive lens with a positive power (positive refractive power) that concentrates light rays, and is a meniscus-shaped glass lens that is thicker towards the center than towards the edge.

[0053] The second lens L2 has a lens surface S3 which is the object side of a spherical surface with positive curvature and a convex shape towards the object, and a lens surface S4 which is the image side of a spherical surface with positive curvature and a concave shape towards the image. The second lens L2 is a positive lens with positive power and is a meniscus-shaped plastic lens.

[0054] The third lens L3 has a spherical lens surface S5 with positive curvature that is convex towards the object side, and a spherical lens surface S6 with positive curvature that is concave towards the image side. The third lens, L3, is a positive lens with negative power that diffuses light rays, and is a meniscus-shaped plastic lens.

[0055] The optical aperture 1 (STOP) has an optical aperture surface S7 on the object side and an optical aperture surface S8 on the image side, forming an opening through which light rays pass and setting the amount of light by the aperture diameter. The optical aperture 1 is made of a non-transparent material and has a thin shape.

[0056] The fourth lens L4 is a plastic lens 400 of Embodiment 1, and has a spherical lens surface S9 (first surface 410) with negative curvature and a concave shape on the object side, and a spherical lens surface S10 (second surface 420) with positive curvature and a concave shape on the image side. The fourth lens L4 is a negative lens with negative power, and is a plastic lens in which the edge side is thicker than the center side.

[0057] The fifth lens L5 has a spherical lens surface S11 (third surface 510) with positive curvature that is convex towards the object side, and a spherical lens surface S12 (fourth surface 520) with negative curvature that is convex towards the image side. The fifth lens L5 is a positive lens with positive power and is made of plastic.

[0058] Furthermore, the image-side lens surface S10 of the fourth lens L4 is bonded to the object-side lens surface S11 of the fifth lens L5 by applying a synthetic resin adhesive or the like, forming a cemented lens with the fourth lens L4 and the fifth lens L5. This cemented lens has positive power. In addition, the area around the joint and edges of the cemented lens may be coated with a solvent-free resin mixed with carbon black or the like. By combining the fourth lens L4 and the fifth lens L5, aberrations can be corrected.

[0059] The sixth lens L6 has a spherical lens surface S13 with positive curvature that is convex towards the object side, and a spherical lens surface S14 with positive curvature that is concave towards the image side. The sixth lens L6 is a positive lens with positive power and is a meniscus-shaped plastic lens.

[0060] Furthermore, the front lens group, comprising the first lens L1, the second lens L2, and the third lens L3, has negative power, while the rear lens group, comprising the fourth lens L4, the fifth lens L5, and the sixth lens L6, has positive power.

[0061] Since the first lens L1 is a glass lens, it has excellent heat resistance and weather resistance, and can withstand natural outdoor environments such as sunlight, temperature and humidity, and rain, and can suppress focus fluctuations due to changes in ambient temperature. The lens surface S1 of the first lens L1 may be coated with a water-repellent or water-resistant coating. The first lens L1 may also be a plastic lens.

[0062] Furthermore, the second lens L2, third lens L3, fourth lens L4, fifth lens L5, and sixth lens L6 can be made of plastic to achieve weight reduction, cost reduction, and impact resistance. At least one of the second lens L2, third lens L3, fifth lens L5, and sixth lens L6 may be a glass lens. This allows the imaging lens system 11 to correct aberrations and suppress, for example, focus shifts at high and low temperatures.

[0063] Furthermore, each lens surface of the first lens L1 to the sixth lens L6 may have a curved surface at least on the surface passing through the optical axis O, similar to the lens surface S6 of the third lens L3, and may have a flange shape with a flat edge. In addition, each lens surface of the first lens L1 to the sixth lens L6 may be an aspherical lens surface.

[0064] The IR cut filter 14 (IRCF) of the camera module 10 is a filter that cuts infrared rays from the light rays coming from the sixth lens L6. The IR cut filter 14 has an IRCF surface S15 and an IRCF surface S16.

[0065] The image sensor 12 (IMG) is an element that captures light rays (images) that have passed through the IR cut filter 14, and is equipped with an imaging surface S17.

[0066] Thus, the camera module 10 comprises an imaging lens system 11, an optical aperture 1, an IR cut filter 14, and an image sensor 12. Each edge may be fixed to the housing (barrel) of the camera module 10 or the imaging lens system 11 by a flat flange or the like. Although the optical aperture 1 is installed integrally with the imaging lens system 11, it is not an essential component of the imaging lens system 11, and the optical aperture 1 is optional.

[0067] Furthermore, the optical aperture 1 is installed between the third lens L3 and the fourth lens L4, but it may be installed at any position between the first lens L1 and the sixth lens L6. In addition, the front lens group has 3 lenses and the rear lens group has 3 lenses, for a total of 6 elements, but this is not limited to this configuration. Furthermore, the imaging lens system 11 may have multiple optical apertures.

[0068] Furthermore, the camera module 10 includes an IR cut filter 14 between the sixth lens L6 and the image sensor 12, but a cover glass (CG) may be provided between the sixth lens L6 and the IR cut filter 14, or between the IR cut filter 14 and the image sensor 12. [Embodiment 3] Figure 10 shows the configuration of an imaging device 50 equipped with the imaging lens system 11 of Embodiment 2. As shown in the figure, the imaging device 50 according to the embodiment includes a camera module 10 that houses the imaging lens system 11 and an image sensor 12 etc. in a housing (not shown), a control unit 52, and a storage unit 54.

[0069] The control unit 52 controls the camera module 10 and processes the electrical signals output from the image sensor 12 of the camera module 10. This control unit 52 may be composed of, for example, a processor unit (PU), RAM, ROM, etc. The control unit 52 may also include one or more processors.

[0070] The processor may include a general-purpose processor that loads a specific program and executes a specific function, and a dedicated processor specialized for a specific process. The dedicated processor may include an application-specific integrated circuit (IC). An application-specific IC is also called an application-specific integrated circuit (ASIC). The processor may also include a programmable logic device. A programmable logic device is also called a programmable logic device (PLD). A PLD may include a field-programmable gate array (FPGA). The control unit 52 may be either a system-on-a-chip (SoC) or a system-in-a-package (SiP) in which one or more processors cooperate.

[0071] The storage unit 54 stores various information or parameters related to the operation of the imaging device 50. The storage unit 54 may be composed of, for example, a semiconductor memory. The storage unit 54 may function as a work memory for the control unit 52. The storage unit 54 may store captured images. The storage unit 54 may store various information or parameters for the control unit 52 to perform detection processing and control based on the captured images. The storage unit 54 may be included in the control unit 52.

[0072] As mentioned above, the camera module 10 captures an image of a subject (object) formed via the imaging lens system 11 using the image sensor 12, and outputs the captured image. The image captured by the camera module 10 is also called the captured image.

[0073] The image sensor 12 may be composed of, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device). The image sensor 12, positioned at the focal point of the imaging lens system 11, has an imaging surface in which multiple pixels are arranged. Each pixel outputs a signal that is specified by current or voltage according to the amount of incident light. The signal output by each pixel is also called imaging data.

[0074] The imaging data may be read out by the camera module 10 for all pixels and taken into the control unit 52 as an image. The image obtained by reading out all pixels is also called the maximum image. The imaging data may be read out by the camera module 10 for some pixels and taken into the image. In other words, the imaging data may be read out from pixels within a predetermined acquisition range. The imaging data read out from pixels within a predetermined acquisition range may be taken into the image. The predetermined acquisition range may be set by the control unit 52. The camera module 10 may obtain the predetermined acquisition range from the control unit 52. The image sensor 12 may capture an image within a predetermined acquisition range from the subject image formed via the imaging lens system 11. Alternatively, the imaging device 50 (imaging camera) may be an imaging system in which the camera module 10 is a separate unit connected by cables or the like. [Embodiment 4] Figure 11 is a schematic diagram of a vehicle 40 equipped with an in-vehicle system comprising an imaging device 50 that includes an imaging lens system according to Embodiment 3 and an image sensor that converts the light focused through the lens into an electrical signal.

[0075] As shown in Figure 11, the vehicle 40, which is a motor vehicle that travels day and night, is equipped with tires, steering, etc., for driving. The mobile vehicle 40 is equipped with an imaging device 50 that can obtain bright, high-resolution images corresponding to a wide field of view. The vehicle 40 is also equipped with an information processing device 42, a display device 43, etc.

[0076] Figure 11 shows several example arrangements illustrating the mounting positions of the imaging device 50 in the vehicle 40. For example, the first imaging device 50a, which is one of the imaging devices 50, may be placed on or near the front bumper as a camera to monitor the area in front of the vehicle 40 while it is in motion. The second imaging device 50b, which is another imaging device 50 that monitors the area in front, may be placed near the rearview mirror inside the vehicle 40. The third imaging device 50c may be placed on the dashboard or inside the instrument panel, etc., as a camera to monitor the driver's driving conditions. The fourth imaging device 50d may be installed at the rear of the vehicle 40 for use as a rear monitor.

[0077] The first imaging device 50a and the second imaging device 50b can be called front cameras. The third imaging device 50c can be called an in-camera. The fourth imaging device 50d can be called a rear camera. The imaging device 50 is not limited to these, and can be installed in various positions, such as a left-side camera that images the left rear side and a right-side camera that images the right rear side, and is an imaging device that can provide a wide field of view with few blind spots. In this way, the imaging lens system 11 within the imaging device 50 can be installed in various positions on the vehicle 40.

[0078] Figure 12 is a diagram showing the configuration of a vehicle 40 equipped with an on-board system 41, which includes an imaging device 50 comprising an imaging lens system 11 according to Embodiment 2 or Embodiment 3 and an image sensor 12 that converts the light focused through the lens into an electrical signal.

[0079] As shown in Figure 12, the imaging device 50 mounted on the vehicle 40 as an automobile can also be called an on-board camera and can be installed in various locations on the vehicle 40. Furthermore, the on-board system 41 equipped with the imaging device 50 etc. mounted on the vehicle 40 as an automobile is also a mobile system equipped with the imaging device 50 etc. mounted on a mobile body. In other words, the mobile body is not limited to the vehicle 40 as an automobile, but includes, for example, a moving bicycle, motorcycle, wheelchair, train, drone, helicopter, airplane, ship, etc.

[0080] As shown in Figure 12, the image signal of the captured image captured by the imaging device 50 is output to the information processing device 42, display device 43, etc. of the vehicle 40 via a cable or bus, etc. Furthermore, the image signal of the captured image may be output to the information processing device, display device, etc. of the control center via wireless or network, etc. The in-vehicle system 41 comprises at least the information processing device 42 and the imaging device 50. The in-vehicle system 41 may also comprise the information processing device 42, the imaging device 50, and the display device 43, etc.

[0081] The information processing device 42 of the vehicle 40 acquires the captured image output from the camera module 10 of the imaging device 50 and processes the image signal of the captured image. The information processing device 42 may also process the captured images acquired by the first imaging device 50a and the second imaging device 50b, which are imaging devices 50 as shown in Figure 11, by combining them. The information processing device 42 may be composed of, for example, a processor unit (PU), RAM, ROM, etc.

[0082] The information processing device 42 recognizes various objects in the captured image, such as people (including the driver of the vehicle 40 captured by the in-camera), other vehicles, other moving objects, animals, roads, and road signs, and generates recognition information such as images of the objects, their type, location, and speed of movement.

[0083] The captured images may be images of the vehicle 40 in the direction of movement, or one or more images that meet predetermined conditions, for example, one image when the vehicle 40 is traveling at a predetermined speed or higher, and multiple images when it is traveling at a speed lower than that.

[0084] The information processing device 42 includes devices that assist the driver in driving. For example, the information processing device 42 includes, but is not limited to, a navigation device, a collision damage mitigation braking device, a distance control device, and a lane departure warning device.

[0085] The display device 43 displays images and other recognition information processed and output by the information processing device 42 as an output device, but it may also notify audio, which is recognition information corresponding to the images and other recognition information, using an audio output device as an output device.

[0086] Furthermore, the display device 43 may employ, but is not limited to, a liquid crystal display (LCD), an organic electro-luminescence (EL) display, or an inorganic EL display. The display device 43 can also directly receive image signals, such as captured images output from an imaging device 50 that captures images from positions difficult for the driver to see, such as a rear camera, for example, a fourth imaging device 50d, and display the captured images to the driver or other occupants. The display device 43 may also be an output device equipped with an audio output device that outputs sound or the like based on the image signal.

[0087] It should be noted that the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. For example, the applications of the imaging lens system 11 of the present invention are not limited to in-vehicle cameras, but can also be used in other applications such as fixed surveillance cameras, digital cameras, and cameras mounted on small electronic devices such as portable mobile phones.

[0088] Furthermore, the present invention includes various embodiments other than those described above. For example, the above-described embodiments are explained in detail to make the present invention easier to understand, and are not necessarily limited to those having all the configurations described.

[0089] Furthermore, the present invention allows for the replacement of parts of the configuration of one embodiment with the configuration of another embodiment, and also allows for the addition of configurations from other embodiments to the configuration of one embodiment. In addition, the present invention allows for the addition, deletion, and replacement of parts of the configuration of each embodiment with other configurations. [Explanation of Symbols]

[0090] 1: Optical aperture (STOP), 10: Camera module, 11: Imaging lens system, 12: Image sensor (IMG), 13: Cover glass (CG), 14: IR cut filter (IRCF), 40: Vehicles, 41: In-vehicle systems, 42: Information processing equipment, 43:Display device, 50, 50a, 50b, 50c, 50d: Imaging devices (imaging cameras, in-vehicle cameras) 52: Control unit, 54: Memory section, 400: Plastic lenses, 410: 1st page, 411, 421: outer edge of the lens, 412, 422: Center of the lens, 420: 2nd side, 423: Edge, 424: Inclined part, 425: Ring section, 430: Outer surface, 431: Side gate marks, 440: Weld line, 500: Lens, 1000: Cavity, 1001: Side gate, 1100: Barrel, 1101: Support part, 1102: Peripheral support part, 1103: Information department, L1: First lens, L2: Second lens, L3: Third lens, L4: Fourth lens, L5: Fifth lens, L6: 6th lens, L7: 7th lens, S1~S6, S9~S14: Lens surface, S7, S8: Optical aperture surface, S15, S16: IRCF surface, S17: Imaging plane.

Claims

1. A plastic lens having a concave first surface, a concave second surface opposite the first surface, and a side gate mark between the first surface and the second surface, The thickness along the optical axis between the central part of the first lens through which the optical axis of the first surface passes and the central part of the second lens through which the optical axis of the second surface passes is thinner than the thickness in the direction parallel to the optical axis between the outer periphery of the first lens outside the central part of the first lens and the outer periphery of the second lens outside the central part of the second lens. The first optical functional surface diameter of the central part of the first lens is smaller than the second optical functional surface diameter of the central part of the second lens. Plastic lenses.

2. In the plastic lens described in claim 1, Having an outer peripheral surface connected to the outer peripheral portion of the first lens, The outer periphery of the second lens has an edge portion that connects to the edge of the central portion of the second lens, and an inclined portion that connects the outer end of the edge portion to the end of the outer surface on the side of the second surface. Plastic lenses.

3. In the plastic lens according to claim 2, The length of the inclined portion in the direction of the optical axis is longer than the length of the outer surface in the direction of the optical axis. Plastic lenses.

4. In the plastic lens according to claim 2, The length of the inclined portion in the direction of the optical axis is longer than the length in the direction perpendicular to the optical axis of the inclined portion. Plastic lenses.

5. In the plastic lens according to claim 2, The length of the edge portion in the direction perpendicular to the optical axis is shorter than the length of the inclined portion in the direction perpendicular to the optical axis. Plastic lenses.

6. In the plastic lens according to claim 2, The depth length along the optical axis in the concave shape of the central part of the second lens is, Shorter than the length of the inclined portion in the direction of the optical axis O, Plastic lenses.

7. In the plastic lens described in claim 1, The depth along the optical axis in the concave shape of the central part of the first lens is shorter than the depth along the optical axis in the concave shape of the central part of the second lens. Plastic lenses.

8. In the plastic lens described in claim 1, The length of the edge portion connected to the central edge of the second lens in the direction perpendicular to the optical axis is, The length of the difference between the distance from the edge of the central part of the second lens to the optical axis and the distance from the edge of the central part of the first lens to the optical axis is greater than the length of the difference between the distance from the edge of the central part of the first lens to the optical axis. Plastic lenses.

9. In the plastic lens described in claim 1, Having an outer peripheral surface connected to the outer peripheral portion of the first lens, The outer periphery of the second lens has an annular portion connected to the edge of the central portion of the second lens, an edge portion that forms a step on the side opposite to the first surface relative to the annular portion, and an inclined portion that connects the outer end of the edge portion to the end of the outer periphery surface on the side of the second surface. Plastic lenses.

10. The plastic lens according to claim 9, A bonding lens comprising a lens that is bonded to the second surface of the plastic lens.

11. A plastic lens according to any one of claims 1 to 9, A camera module comprising: an image sensor that converts light collected through the aforementioned plastic lens into an electrical signal.

12. An imaging device comprising: a camera module according to claim 11; a control unit for controlling the camera module; and a storage unit for storing information for the control unit to perform control.

13. An in-vehicle system comprising a camera module according to claim 11, and an information processing device that recognizes an object in an image captured by the camera module and generates recognition information.

14. A mobile body comprising: a camera module according to claim 11; an information processing device that recognizes an object in an image captured by the camera module and generates recognition information; and an output device that outputs the recognition information.

Images