Optical system and imaging device

Abstract

In an optical system that guides incident light to an image sensor, the optical system is miniaturized. [Solution] The imaging device comprises an optical system and an image sensor. In the imaging device, the optical system includes a first lens. In the optical system, the first curved surface portion of the first lens has a predetermined shape such that the planar shape of the first curved surface portion when viewed from the optical axis direction is not circular. Also, the outer circumference of the first lens when viewed from the optical axis direction is rectangular. The image sensor generates image data by photoelectric conversion of incident light from the optical system. The first lens comprises a first curved surface portion and a flange portion around the first curved surface portion. The first curved surface portion comprises an aspherical portion through which the effective light beam passes and a connecting inclined portion for connecting the aspherical portion and the flange portion.

Description

[Technical Field]

[0001] This technology relates to optical systems. More specifically, it relates to optical systems that guide incident light to an image sensor, and to imaging devices. [Background technology]

[0002] In recent years, research and development have been progressing on the optical systems used in imaging devices mounted on mobile devices such as smartphones and HMDs (Head Mounted Displays). For example, an optical system with a rectangular flange surrounding a circular curved surface has been proposed (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2003-156601 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In the conventional technology described above, the flange portion is made rectangular, which allows it to be supported by a coating jig, thereby facilitating coating. However, with the optical system described above, it is difficult to further miniaturize the optical system.

[0005] This technology was developed in light of these circumstances, and aims to miniaturize the optical system used to guide incident light to an image sensor. [Means for solving the problem]

[0006] This technology was developed to solve the aforementioned problems, and its first aspect is that it comprises a first lens whose planar shape of the first curved surface portion viewed from the optical axis direction is a predetermined shape that is not circular, and whose outer circumference viewed from the optical axis direction is rectangular, and the first lens comprises the first curved surface portion and a flange portion around the first curved surface portion, and the first curved surface portion comprises an aspherical portion through which the effective light beam passes and a connecting inclined portion for connecting the aspherical portion and the flange portion. This results in the ability to miniaturize the optical system.

[0007] Furthermore, in this first aspect, the predetermined shape may be rectangular. This has the effect of enabling miniaturization of the optical system having a first lens with a rectangular curved surface.

[0008] Furthermore, in this first aspect, the predetermined shape may have a plurality of sides, and at least one of the plurality of sides may be curved such that it is concave with respect to the center point of the first lens. This has the effect of enabling miniaturization of an optical system that includes a first lens in which at least one of the plurality of sides of the first curved surface is curved such that it is concave with respect to the center point of the first lens.

[0009] Furthermore, in this first aspect, the predetermined shape may have a plurality of sides, and at least one of the plurality of sides may be curved so as to be convex with respect to the center point of the first lens. This has the effect of enabling miniaturization of an optical system that includes a first lens in which at least one of the plurality of sides of the first curved surface is curved so as to be convex with respect to the center point of the first lens.

[0010] Furthermore, in this first aspect, the connecting inclined portion may be present only on one side of the first lens.

[0011] Furthermore, in this first aspect, the inclination angle of the connecting inclined portion may be between 25 and 65 degrees.

[0012] Furthermore, in this first aspect, the distance from the outer circumference of the first curved surface to the outer circumference of the first lens may be 0.1 millimeters or less. This has the effect of enabling miniaturization of an optical system that includes a first lens in which the distance from the outer circumference of the first curved surface to the outer circumference of the first lens is 0.1 millimeters or less.

[0013] Furthermore, in this first aspect, a portion of the outer circumference of the first curved surface, when viewed from the direction of the optical axis, may overlap with the outer circumference of the first lens. This has the effect of enabling miniaturization of an optical system that includes a first lens in which a portion of the outer circumference of the first curved surface overlaps with the outer circumference of the first lens.

[0014] Furthermore, in this first aspect, the first lens may be a lens molded from a thermoplastic resin. This has the effect of making it possible to miniaturize the optical system equipped with the first lens molded from a thermoplastic resin.

[0015] Furthermore, in this first aspect, the optical system may further include a second lens having a second curved surface portion with a circular planar shape when viewed from the optical axis direction, and a third lens having a third curved surface portion, arranged in the order of the third lens, the second lens, and the first lens from the object side. This has the effect of making the three-group optical system smaller.

[0016] Furthermore, in this first aspect, the planar shape of the third curved surface when viewed from the direction of the optical axis may be circular. This has the effect of enabling miniaturization of the optical system in which the third curved surface comprises a circular third lens.

[0017] Furthermore, in this first aspect, the planar shape of the third curved surface when viewed from the optical axis direction may not be circular. This has the effect of enabling miniaturization of the optical system equipped with a third lens in which the third curved surface is not circular.

[0018] Moreover, a second aspect of the present technology is an optical system including a first lens having a predetermined shape where the planar shape of the first curved surface portion when viewed from the optical axis direction does not correspond to a circle and an outer periphery when viewed from the optical axis direction is rectangular, and an image sensor that photoelectrically converts incident light from the optical system to generate image data. The imaging device includes the first lens, and the first lens includes the first curved surface portion and a flange portion around the first curved surface portion. The first curved surface portion includes an aspherical surface portion through which an effective light beam passes and a connecting inclined portion for connecting the aspherical surface portion and the flange portion. This brings about an effect that the optical system in the imaging device can be miniaturized.

[0019] Also, in this second aspect, the predetermined shape may be rectangular.

[0020] Also, in this second aspect, the inclination angle of the connecting inclined portion may be an angle between 25 degrees and 65 degrees.

[0021] Also, in this second aspect, the imaging device may further include a plurality of lenses including the first lens.

[0022] Moreover, a third aspect of the present technology is an optical system including a plurality of lenses including a first lens, each of the plurality of lenses having an aspherical surface portion through which an effective light beam passes, and at least the first lens among the plurality of lenses having an outer periphery that is rectangular when viewed from the optical axis direction, and having the largest aspherical surface portion among the plurality of lenses in a plan view.

[0023] Also, in this third aspect, the first lens may have a first curved surface portion including the aspherical surface portion, and the planar shape of the first curved surface portion when viewed from the optical axis direction may be a predetermined shape that does not correspond to a circle.

[0024] {{END]] Also, in this third aspect, the predetermined shape may be rectangular.

[0025] Furthermore, in this third aspect, the first lens further comprises a flange portion around the first curved portion and a connecting inclined portion for connecting the aspherical portion and the flange portion, wherein the inclination angle of the connecting inclined portion may be between 25 and 65 degrees. [Brief explanation of the drawing]

[0026] [Figure 1] This is an example of a cross-sectional view of the imaging device in the first embodiment of this technology. [Figure 2] This figure shows an example of the cross-sectional shape of a light beam passing through an optical system in the first embodiment of this technology. [Figure 3] This is an example of a cross-sectional view and a top view of the object-side lens in the first embodiment of this technology. [Figure 4] This is an example of a cross-sectional view and a top view of the second lens from the object side in the first embodiment of this technology. [Figure 5] This is an example of a cross-sectional view and a top view of the image-plane lens in the first embodiment of this technology. [Figure 6] This is an example of a top view of an image sensor in the first embodiment of this technology. [Figure 7] This is an example of a top view of the image-plane lens in the first embodiment of this technology. [Figure 8] This figure illustrates the relationship between the shape of the image sensor and the shape of the light beam of the lens on the image plane side in the first embodiment of this technology. [Figure 9] This is an example of a top view of the image-plane lens in a comparative example. [Figure 10] This is a diagram illustrating the process of thermocast molding in the first embodiment of this technology. [Figure 11] This is a diagram illustrating the process of individualizing the parts in the first embodiment of this technology. [Figure 12] This is a diagram illustrating the UV (Ultra-Violet) imprint molding process in the first embodiment of this technology. [Figure 13]This is a diagram illustrating the injection molding process in the first embodiment of this technology. [Figure 14] This is an example of a cross-sectional view and a top view of the image-plane lens in the second embodiment of this technology. [Figure 15] This is an example of a cross-sectional view of the imaging device in the third embodiment of this technology. [Figure 16] This is an example of a cross-sectional view and a top view of the object-side lens in the third embodiment of this technology. [Figure 17] This is an example of a cross-sectional view and a top view of the image-plane lens in the third embodiment of this technology. [Figure 18] This is an example of a cross-sectional view and a top view of the image-plane lens in the fourth embodiment of this technology. [Figure 19] This is an example of a cross-sectional view and a top view of the image-plane lens in the fifth embodiment of this technology. [Modes for carrying out the invention]

[0027] The following describes the embodiments for implementing this technology. The description will proceed in the following order. 1. First embodiment (an example in which the outer circumference of a lens with a rectangular curved surface is made rectangular) 2. Second embodiment (an example in which the outer circumference of a lens, with all four sides of the curved surface curved in a convex shape, is rectangular) 3. Third embodiment (an example in which the outer circumference of a lens, with the four sides of the connecting inclined section curved in a convex shape, is rectangular) 4. Fourth embodiment (an example in which the outer circumference of a lens, with the four sides of the connecting inclined section curved in a concave shape, is rectangular) 5. Fifth embodiment (an example in which the outer circumference of a lens, with eight sides of the connecting inclined section curved in a concave shape, is rectangular)

[0028] <1. First Embodiment> [Example configuration of an imaging device] Figure 1 is an example of a cross-sectional view of an imaging device 100 in an embodiment of this technology. This imaging device 100 is a device for capturing image data and comprises an optical system 200 and an image sensor 110. The optical system 200 collects incident light and guides it to the image sensor 110 and comprises lenses 210, 220, and 230. The imaging device 100 is installed, for example, in a mobile device such as a smartphone or HMD.

[0029] Hereafter, the optical axis of optical system 200 will be referred to as the "Z-axis," and a predetermined axis perpendicular to the Z-axis will be referred to as the "X-axis." The axis perpendicular to both the X-axis and the Z-axis will be referred to as the "Y-axis."

[0030] In the optical system 200, the lenses are arranged in the order of lens 230, lens 220, and lens 210, from the object side towards the image plane side of the image sensor 110.

[0031] [Example of optical system configuration] Figure 2 shows an example of the cross-sectional shape of a light beam passing through an optical system in the first embodiment of this technology. As illustrated in the figure, incident light passes through lenses 230, 220, and 210, respectively, and enters the image plane of the image sensor 110. In the figure, only the portions through which effective incident light passes from lenses 230 and 220 are shown. Here, "effective light beam" means the portion of the light beam passing through the optical system 200 that is focused by the optical system 200. The lenses 230, 220, and 210 described above are manufactured, for example, by molding a thermoplastic resin.

[0032] Figure 3 shows an example of a cross-sectional view and a top view of the object-side lens 230 in the first embodiment of this technology. This lens 230 comprises a curved surface portion 231 on which at least one of its surfaces is curved, and a flange portion 232 around it. The flange portion 232 is the part of the lens 230 whose center point is the same as that of the curved surface portion 231, whose outer circumference is longer than that of the curved surface portion 231, and whose two surfaces are flat. An aperture (not shown) is also provided around the lens 230. The curved surface portion 231 is transparent, but the flange portion 232 may be transparent or light-shielding.

[0033] As illustrated in the figure, the planar shape of the curved portion 231 when viewed from the Z-axis (i.e., optical axis) direction is circular. The shaded portion shows the planar shape of the effective light beam, which is also circular. The planar shape of the flange portion 232 is omitted, but its outer circumference is, for example, rectangular. Lens 230 is an example of the third lens described in the claims, and curved portion 231 is an example of the third curved portion described in the claims.

[0034] Figure 4 shows an example of a cross-sectional view and a top view of the second lens 220 from the object side in the first embodiment of this technology. This lens 220 comprises a curved surface portion 221 on which at least one of its surfaces is curved, and a flange portion 222 around it. The flange portion 222 is the part of the lens 220 whose center point is the same as that of the curved surface portion 221, whose outer circumference is longer than that of the curved surface portion 221, and whose two surfaces are flat. The curved surface portion 221 is transparent, but the flange portion 222 may be transparent or light-shielding. A connecting inclined portion 221-2 may be provided to connect the aspherical portion 221-1 and the flange portion 222. The connecting inclined portion can function as a support structure to prevent the lenses from interfering with each other when stacking lenses. If the lowest part of the curved surface portion of the lens protrudes further towards the image sensor than the flange portion on the image sensor side of the lens, the lenses may interfere with each other. For example, in Figure 1, if the connecting inclined portion of lens 220 is short and the lowest part of lens 220 protrudes below the flange portion of lens 220, the lowest part of lens 220 will interfere with the upper surface of lens 210. The steeper the inclination angle θ of the connecting inclined portion, the more it contributes to miniaturization of the imaging device. However, if the inclination angle θ becomes 90 degrees, lens molding becomes difficult. Considering both miniaturization and ease of molding, an inclination angle θ of the connecting inclined portion is preferably between 25 and 65 degrees.

[0035] As illustrated in the figure, the planar shape of the curved portion 221 when viewed from the Z-axis (optical axis) direction is a rounded rectangle. The shaded portion shows the planar shape of the effective light beam, which is also a rounded rectangle. Note that the planar shape of the curved portion 221 and the light beam shape may be circular. The planar shape of the flange portion 222 is omitted, but its outer circumference is, for example, rectangular. Lens 220 is an example of the second lens described in the claims, and curved portion 221 is an example of the second curved portion described in the claims.

[0036] Figure 5 shows an example of a cross-sectional view and a top view of the image-plane lens 210 in the first embodiment of this technology. This lens 210 comprises a curved surface portion 211 on which at least one of its surfaces is curved, and a flange portion 212 around it. The flange portion 212 is the part of the lens 210 whose center point is the same as that of the curved surface portion 211, whose outer circumference is longer than that of the curved surface portion 211, and whose two surfaces are flat. The curved surface portion 211 is transparent, but the flange portion 212 may be transparent or light-shielding.

[0037] As illustrated in the figure, the planar shape of the curved portion 211 when viewed from the Z-axis (optical axis) direction is not circular, but rather rectangular. Note that the planar shape of the curved portion 211 is not limited to a rectangle, but may be close to a rectangle, as long as it is not circular.

[0038] Furthermore, the planar shape of the outer circumference of the flange portion 212 (in other words, the outer circumference of the lens 210) when viewed from the Z-axis (optical axis) direction is rectangular. In the top view, the gray area represents the flange portion 212. If d is the width, which is the distance from the outer circumference of the curved portion 211 to the outer circumference of the lens 210, then d is preferably a value that satisfies the following equation. It is preferable that d is one-tenth or less of the length of the lens side (for example, the length of the long side of a rectangular lens). Also, as shown in Figure 5, the width d on the short side and the width d on the long side of the rectangular lens shown in Figure 5 may be different. d ≤ 0.1 millimeters (mm) ... Formula 1

[0039] In the figure, the distance from each of the four sides of the curved surface 211 to the outer circumference of the lens 210 is greater than 0. However, the distance d from a portion of these four sides (e.g., two sides) to the outer circumference of the lens 210 may be 0 millimeters. In other words, a portion of the four sides may overlap with the outer circumference of the lens 210.

[0040] Lens 210 is an example of the first lens described in the claims, and curved surface portion 211 is an example of the first curved surface portion described in the claims.

[0041] Figure 6 is an example of a top view of the image-plane lens 210 in the first embodiment of this technology. In the figure, the shaded area shows the planar shape of the effective light beam. The gray area shows the flange portion 212. As illustrated in the figure, the outer circumferences of the curved portion 211 and the flange portion 212 are rectangular, and the light beam shape is also rectangular. The area of ​​the light beam shape is approximately the same as that of the curved portion 211, but for the sake of clarity, the area of ​​the light beam shape is shown as slightly smaller than that of the curved portion 211 in the figure.

[0042] Figure 7 shows an example of a cross-sectional view and a top view of an image sensor 110 in the first embodiment of this technology. As illustrated in the figure, the planar shape of the image sensor 110 when viewed from the Z-axis (optical axis) direction is rectangular. In addition, multiple pixels (not shown) are arranged in a two-dimensional grid on the image plane of the image sensor 110.

[0043] Here, for miniaturization of the optical system 200, miniaturization of each lens component within the optical system 200 such as the lens 210 is necessary. To miniaturize the lens component alone to the maximum extent, it is necessary to make the area outside the region of the actual light beam on the lens, in other words, the region through which the light that forms an image on the image sensor 110 passes, as small as possible. Also, considering the shape of the actual light beam on the lens, the shape varies depending on the position of the lens on the optical axis. When the shape of the image sensor 110 is rectangular, it is common to design such that the light beam of the lens at a position farther from the aperture approaches a rectangle and its size becomes larger. Therefore, it is considered that the lens can be miniaturized most by making the outer periphery of the lens 210 at the position farthest from the aperture rectangular.

[0044] FIG. 8 is a diagram for explaining the relationship between the shape of the image sensor 110 and the light beam shape of the lens 210 on the image plane side in the first embodiment of the present technology.

[0045] Let the dimensions of the curved surface portion 211 of the lens 210 in the X-axis direction and the R-axis direction be R , Y and R Y and let the diagonal dimension be R D Also, let the dimensions of the image sensor 110 in the X-axis direction and the R-axis direction be S X and S Y and let the diagonal dimension be S D Also, the shape of the light beam incident on the image plane of the image sensor 110 from the curved surface portion 211 substantially coincides with that image plane. In this case, for example, the following equations hold. R X ≈R D *(S X / S D ) ··· Equation 2 R Y ≈R D *(S Y / S D ) ··· Equation 3 <000-0220> As illustrated in the figure, by making the shape of the lens 210 on the image plane side rectangular, the shape of the light beam that forms an image on the image plane can be made closer to that image plane.

[0047] Here, we consider an optical system where the planar shape of the curved portion of the lens on the image plane side is circular as a comparative example.

[0048] Figures 9a and 9b show an example of a top view of the image-plane lens in the comparative example. In this comparative example, the image-plane lens 210 comprises a circular curved portion 211 and a flange portion 212.

[0049] Figure 9a shows a top view of the lens 210 when the outer circumference of the flange portion 212 (in other words, the outer circumference of the lens 210) is circular. Figure 9b shows a top view of the lens 210 when the outer circumference of the flange portion 212 (the outer circumference of the lens 210) is rectangular. The shaded area of ​​the rectangle indicates the portion through which the effective light beam passes, and the gray area indicates the flange portion 212.

[0050] As illustrated in Figures 9a and 9b, in the comparative example, only a portion of the light beam passing through the curved surface 211 is imaged onto the image plane, resulting in a wasted area between the shaded portion through which the effective light beam passes and the outer periphery of the curved surface 211.

[0051] In contrast, as illustrated in Figure 6, if the curved portion 211 of the object-side lens 210 is made rectangular, and the outer circumference of the lens 210 is also made rectangular, the wasted area shown in the comparative example can be minimized. In this way, by optimizing the planar shape of the curved portion 211 to match the effective light beam shape, the size of the lens 210 can be reduced to its limit.

[0052] [Manufacturing method for optical systems] Next, the manufacturing method of the optical system 200 will be described with reference to Figures 10a to 13c.

[0053] As illustrated in Figure 10a, the mold 500 is coated with the lens molding material 502 by the dispenser 501. For example, a thermoplastic resin is used as the molding material 502. The shape of the surface side of the cross-section of this mold 500 corresponds to the shape of one of the two sides of each of the multiple lenses.

[0054] Then, as illustrated in Figure 10b, the mold is clamped using the mold 503. The shape of the surface side of this mold 503 corresponds to the shape of the other side of each of the multiple lenses.

[0055] As illustrated in Figure 10c, the molding material 502 hardens upon heating, forming the wafer 504. In this way, the wafer 504 is formed by thermal casting.

[0056] Figure 11a shows a top view of wafer 504. This wafer 504 includes the curved portions 211 of multiple lenses.

[0057] Then, as illustrated in Figure 11b, the wafer 504 is fragmented into multiple lenses 210. In this way, the lenses 210 are formed at the wafer level.

[0058] Lenses 220 and 230 are formed by a similar process, and the optical system 200 is manufactured by assembling them.

[0059] Although Figures 10a to 10c show the use of thermal casting, the method is not limited to this technique.

[0060] For example, as illustrated in Figure 12, UV (Ultraviolet) imprint molding can be used instead of thermal casting. In this case, an ultraviolet-curing resin is used as the molding material 502. The molding material 502 is then applied to the mold 500 and irradiated with ultraviolet light. This hardens the molding material 502, and a wafer is formed.

[0061] Alternatively, injection molding can be used instead of thermal casting, as illustrated in Figures 13a to 13c.

[0062] In this case, as illustrated in Figure 13a, the mold 503 with the gate formed on it is pressed against the mold 500.

[0063] Then, as illustrated in Figure 13b, the molding material 502 is filled through the gate and cooled.

[0064] Then, as illustrated in Figure 13c, the wafer 504 is removed and the molding material 505 at the gate portion is cut off.

[0065] In thermal casting and UV imprint molding, a wide range of d is necessary due to the need for surface accuracy in curved areas and the requirement for coating. Therefore, when manufacturing an optical system 200 that satisfies Equation 1, it is preferable to use injection molding.

[0066] Thus, according to the first embodiment of this technology, since the planar shape of the curved portion 211 is rectangular around the outer circumference of the rectangular lens 210, the optical system 200 can be made smaller compared to the comparative example.

[0067] <2. Second Embodiment> In the first embodiment described above, the planar shape of the curved portion 211 of the image-plane lens 210 was rectangular, but the optical system is not limited to this shape. The optical system 200 in this second embodiment differs from the first embodiment in that the edges of the curved portion 211 are curved in a convex shape with respect to the center of the lens 210.

[0068] Figure 14 shows an example of a cross-sectional view and a top view of the image-plane lens 210 in a second embodiment of this technology. In this second embodiment, the planar shape of the curved portion 211 has multiple sides, and at least one of these sides is curved to be convex with respect to the center point P0 of the lens 210. Note that "convex shape" can also be expressed as the shape of the side being an arc, and the center point P0 being located between the center point P1 of a circle whose circumference is part of the arc and the side.

[0069] In the example shown in the figure, the curved surface portion 211 is a figure close to a rectangle with four sides, and all of these sides are curved in a convex shape. Therefore, the distance d from the outer circumference of the curved surface portion 211 to the outer circumference of the flange portion 212 is not constant, but the minimum d is assumed to satisfy Equation 1. Note that the curved sides may be only a part of the four sides (for example, only two sides).

[0070] Thus, according to the second embodiment of this technology, since the outer circumference of the lens 210, which is curved such that at least one side of the curved surface portion 211 is convex with respect to the center of the lens 210, is made rectangular, the optical system 200 including the lens 210 can be miniaturized.

[0071] <3. Third Embodiment> In the first embodiment described above, the planar shape of the curved portion 211 of the lens 210 on the image plane side was rectangular, but the invention is not limited to this shape. The connecting inclined portion can function as a support structure to prevent the lenses from interfering with each other when stacking lenses, similar to the first embodiment. If the lowest part of the curved portion of the lens protrudes further towards the image sensor than the flange portion on the image sensor side of the lens, the lenses may interfere with each other. The steeper the inclination angle θ of the connecting inclined portion, the more it contributes to miniaturization of the imaging device. However, if the inclination angle θ becomes 90 degrees, lens molding becomes difficult. Considering both miniaturization and ease of molding, the inclination angle θ of the connecting inclined portion is preferably between 25 and 65 degrees.

[0072] Figures 15a and 15b are examples of cross-sectional views of the imaging device 100 in a third embodiment of the present technology. In this third embodiment, the shapes of the lenses 230 and 210 in the optical system 200 differ from those in the first embodiment. In Figures 15a and 15b, the lens 230 has a convex upper surface and a concave lower surface, while the lens 220 has a flat upper surface and a convex lower surface. The difference between Figures 15a and 15b is that in Figure 15a, the lens 210 has a concave upper surface and a convex lower surface, whereas in Figure 15b, the lens 210 has a convex upper surface and a concave lower surface.

[0073] Figure 16 shows an example of a cross-sectional view and a top view of the object-side lens 230 in a third embodiment of the present technology. As illustrated in the figure, the planar shape of the curved portion 231 of the lens 230 has four sides, two of which are straight lines, and the remaining two sides are curved to be convex with respect to the center point of the lens 230.

[0074] Figure 17 shows an example of a cross-sectional view and a top view of the image-plane lens 210 in a third embodiment of the present technology. In the third embodiment, the curved portion 211 of the lens 210 consists of an aspherical portion 211-1 and a connecting inclined portion 211-2. The aspherical portion 211-1 is the portion through which the effective light beam passes, and the connecting inclined portion 211-2 is the portion having an inclination that connects the aspherical portion 211-1 and the flange portion 212.

[0075] The planar shape of the aspherical portion 211-1 is a figure close to a rectangle, with each of its four sides curved so as to be convex with respect to the center point of the lens 210. Similarly, the outer circumference of the planar shape of the connecting inclined portion 211-2 is a figure close to a rectangle, with each of its four sides curved so as to be convex with respect to the center point of the lens 210.

[0076] When manufacturing the lens 210 with the shape shown in the figure, injection molding is preferable because the surface accuracy of the curved portion 211 is required. The same applies to the fourth and fifth embodiments described later.

[0077] Thus, according to the third embodiment of this technology, since the outer circumference of the curved lens 210 is made rectangular so that each of the four sides of the curved surface portion 211 is convex with respect to the center point of the lens 210, the optical system 200 including the lens 210 can be miniaturized.

[0078] <4. Fourth Embodiment> In the third embodiment described above, the four sides of the connecting inclined portion 211-2 were curved to be convex, but the optical system is not limited to this shape. The optical system 200 in this fourth embodiment differs from the third embodiment in that the four sides of the connecting inclined portion 211-2 are curved to be concave.

[0079] Figure 18 shows an example of a cross-sectional view and a top view of the image-plane lens 210 in the fourth embodiment of this technology. In the fourth embodiment, the planar shape of the aspherical portion 211-1 is the same as in the third embodiment. On the other hand, the outer circumference of the planar shape of the connecting inclined portion 211-2 is a figure close to a rectangle, and each of the four sides is curved so as to be concave with respect to the center point of the lens 210.

[0080] Thus, according to the fourth embodiment of this technology, since the outer circumference of the lens 210, which is curved such that each of the four sides of the curved surface portion 211 is concave with respect to the center point of the lens 210, is made rectangular, the optical system 200 including the lens 210 can be miniaturized.

[0081] <5. Fifth Embodiment> In the third embodiment described above, the four sides of the connecting inclined portion 211-2 were curved to be convex, but the optical system is not limited to this shape. The optical system 200 in this third embodiment differs from the third embodiment in that the eight sides of the aspherical portion 211-1 and the connecting inclined portion 211-2 are curved to be concave.

[0082] Figure 19 shows an example of a cross-sectional view and a top view of the image-plane lens 210 in the fifth embodiment of this technology. In the fifth embodiment, the planar shape of the aspherical portion 211-1 is the same as in the third embodiment. On the other hand, the outer circumference of the planar shape of the connecting inclined portion 211-2 has eight sides, and each side is curved so as to be concave with respect to the center point of the lens 210.

[0083] Thus, according to the fifth embodiment of this technology, the outer circumference of the lens 210, which is curved such that the eight sides of the connecting inclined portion 211-2 are concave with respect to the center point of the lens 210, is made rectangular, and the optical system 200 including the lens 210 can be miniaturized.

[0084] The embodiments described above are merely examples of how to realize this technology, and there is a corresponding relationship between the matters in the embodiments and the inventive features in the claims. Similarly, there is a corresponding relationship between the inventive features in the claims and the matters in the embodiments of this technology that bear the same name. However, this technology is not limited to the embodiments and can be realized by making various modifications to the embodiments without departing from the gist of the technology.

[0085] The effects described herein are merely illustrative and not limited to those described herein, and other effects may also occur.

[0086] Furthermore, this technology can also be configured as follows. (1) The first lens comprises a predetermined shape in which the planar shape of the first curved surface portion when viewed from the direction of the optical axis is not circular, and the outer circumference when viewed from the direction of the optical axis is rectangular. The first lens comprises a first curved surface portion and a flange portion surrounding the first curved surface portion. The first curved portion comprises an aspherical portion through which the effective light beam passes, and a connecting inclined portion for connecting the aspherical portion and the flange portion. optical system. (2) The predetermined shape is rectangular. The optical system described in (1) above. (3) The predetermined shape has a plurality of sides, and at least one of the plurality of sides is curved in a concave shape with respect to the center point of the first lens. The optical system described in (1) above. (4) The predetermined shape has a plurality of sides, and at least one of the plurality of sides is curved to be convex with respect to the center point of the first lens. The optical system described in (1) above. (5) The optical system according to (1) wherein the connecting inclined portion is present only on one side of the first lens. (6) The angle of inclination of the connecting inclined section is between 25 degrees and 65 degrees. The optical system described in (1) above. (7) The optical system according to any one of (1) to (6), wherein the distance from the outer circumference of the first curved surface to the outer circumference of the first lens is 0.1 millimeters or less. (8) When viewed from the optical axis direction, a portion of the outer circumference of the first curved surface overlaps with the outer circumference of the first lens. The optical system described in any of (1) to (7) above. (9) The first lens is a lens made by molding a thermoplastic resin. The optical system described in any of (1) to (8) above. (10) A second lens having a second curved surface portion whose planar shape is circular when viewed from the optical axis direction, A third lens having a third curved section Furthermore, it is equipped with, The lenses are arranged in the order of the third lens, the second lens, and the first lens from the object side. The optical system described in any of (1) to (9) above. (11) The planar shape of the third curved surface when viewed from the direction of the optical axis is circular. The optical system described in (10) above. (12) The planar shape of the third curved portion when viewed from the direction of the optical axis is not a circular shape. The optical system described in (10) above. (13) An optical system comprising a first lens having a predetermined shape in which the planar shape of the first curved surface portion when viewed from the direction of the optical axis is not circular, and the outer circumference when viewed from the direction of the optical axis is rectangular, An image sensor that generates image data by converting incident light from the optical system into photoelectric light, It is equipped with, The first lens comprises a first curved surface portion and a flange portion surrounding the first curved surface portion. The first curved portion comprises an aspherical portion through which the effective light beam passes, and a connecting inclined portion for connecting the aspherical portion and the flange portion. Imaging device. (14) The imaging device according to (13) wherein the predetermined shape is rectangular. (15) The optical system according to (13) or (14), wherein the angle of inclination of the connecting inclined portion is between 25 degrees and 65 degrees. (16) The imaging device according to (13), further comprising a plurality of lenses including the first lens. (17) Equipped with multiple lenses including a first lens, Each of the aforementioned lenses has an aspherical portion through which an effective light beam passes. An optical system in which at least the first lens among the plurality of lenses has a rectangular outer circumference when viewed from the optical axis direction, and the largest aspherical portion among the plurality of lenses in a plan view. (18) The first lens has a first curved portion including the aspherical portion, The planar shape of the first curved surface when viewed from the optical axis direction is a predetermined shape that does not correspond to a circle. The optical system described in (17) above. (19) The optical system according to (18) wherein the predetermined shape is rectangular. (20) The optical system according to (18), wherein the first lens further comprises a flange portion around the first curved portion and a connecting inclined portion for connecting the aspherical portion and the flange portion, and the inclination angle of the connecting inclined portion is between 25 and 65 degrees. [Explanation of Symbols]

[0087] 100 Imaging device 110 Image Sensor 200 Optical system 210, 220, 230 lenses 211, 221, 231 Curved section 211-1, 221-1 Aspherical part 211-2, 221-2 Connecting inclined section 212, 222, 232 Flange section 500, 503 molds 501 Dispenser 502, 505 Molding materials 504 wafer

Claims

1. The first lens comprises a predetermined shape in which the planar shape of the first curved surface portion viewed from the optical axis direction is not circular, and the outer circumference viewed from the optical axis direction is rectangular. The first lens comprises a first curved surface portion and a flange portion surrounding the first curved surface portion. The first curved portion comprises an aspherical portion through which an effective light beam passes, and a connecting inclined portion for connecting the aspherical portion and the flange portion. optical system.

2. The predetermined shape is rectangular. The optical system according to claim 1.

3. The predetermined shape has a plurality of sides, and at least one of the plurality of sides is curved such that it is concave with respect to the center point of the first lens. The optical system according to claim 1.

4. The predetermined shape has a plurality of sides, and at least one of the plurality of sides is curved so as to be convex with respect to the center point of the first lens. The optical system according to claim 1.

5. The optical system according to claim 1, wherein the connecting inclined portion is present only on one side of the first lens.

6. The inclination angle of the aforementioned connecting inclined section is between 25 and 65 degrees. The optical system according to claim 1.

7. The optical system according to claim 1, wherein the distance from the outer circumference of the first curved surface to the outer circumference of the first lens is 0.1 millimeters or less.

8. When viewed from the optical axis direction, a portion of the outer circumference of the first curved surface overlaps with the outer circumference of the first lens. The optical system according to claim 1.

9. The first lens is a lens molded from thermoplastic resin. The optical system according to claim 1.

10. A second lens having a second curved surface portion whose planar shape is circular when viewed from the optical axis direction, A third lens having a third curved surface and Furthermore, it is equipped with, The lenses are arranged in the order of the third lens, the second lens, and the first lens from the object side. The optical system according to claim 1.

11. The planar shape of the third curved portion, as viewed from the optical axis direction, is circular. The optical system according to claim 10.

12. The planar shape of the third curved portion, when viewed from the optical axis direction, is not circular. The optical system according to claim 10.

13. An optical system comprising a first lens having a predetermined shape in which the planar shape of the first curved surface portion viewed from the optical axis direction is not circular, and the outer circumference viewed from the optical axis direction is rectangular, An image sensor that generates image data by converting incident light from the optical system into photoelectric light, It is equipped with, The first lens comprises a first curved surface portion and a flange portion surrounding the first curved surface portion. The first curved portion comprises an aspherical portion through which an effective light beam passes, and a connecting inclined portion for connecting the aspherical portion and the flange portion. Imaging device.

14. The imaging device according to claim 13, wherein the predetermined shape is rectangular.

15. The optical system according to claim 13, wherein the inclination angle of the connecting inclined portion is between 25 degrees and 65 degrees.

16. The imaging apparatus according to claim 13, further comprising a plurality of lenses including the first lens.

17. Equipped with multiple lenses, including a first lens, Each of the aforementioned lenses has an aspherical portion through which an effective light beam passes. An optical system in which at least the first lens among the plurality of lenses has a rectangular outer circumference when viewed from the optical axis direction, and the largest aspherical portion among the plurality of lenses in a plan view.

18. The first lens has a first curved portion including the aspherical portion, The planar shape of the first curved surface when viewed from the optical axis direction is a predetermined shape that does not correspond to a circle. The optical system according to claim 17.

19. The optical system according to claim 18, wherein the predetermined shape is rectangular.

20. The optical system according to claim 18, wherein the first lens further comprises a flange portion around the first curved portion and a connecting inclined portion for connecting the aspherical portion and the flange portion, and the inclination angle of the connecting inclined portion is between 25 degrees and 65 degrees.

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