Optical system, optical device, and imaging device

Abstract

The present invention provides an optical system with high resolution, high optical performance and miniaturization, an optical device having the optical system, a photographing device, and a manufacturing method of the optical system and the photographing device. The optical system (UL) of a camera module (10) mounted on an optical device such as a camera (60) includes a correction member, a first reflecting portion (12a), and a second reflecting portion (13a), and forms an image of an object. The correction member has a correction surface (11a). The first reflecting surface (12a) reflects the light that has passed through the correction surface (11a). The second reflecting surface (13a) reflects the light reflected by the first reflecting surface (12a). Among them, the optical system (UL) satisfies a predetermined condition.

Description

Technical Field

[0001] The present invention relates to an optical system, an optical device, a photographing device, and a method for manufacturing an optical system and a photographing device. Background Art

[0002] Conventionally, a photographing device that has been miniaturized by using a reflective optical system has been proposed (see, for example, Patent Document 1). However, further miniaturization is required.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2018-109673 Summary of the Invention

[0006] The optical system according to the first aspect of the present invention includes an incident surface, a first reflection portion, and a second reflection portion, and forms an image of an object. The incident surface allows light from the object side to enter, the first reflection portion reflects the light that has passed through the incident surface, and the second reflection portion reflects the light that has been reflected by the first reflection portion. Among them, the optical system satisfies the condition of the following formula:

[0007] TL < 15.0 mm

[0008] Among them,

[0009] TL: The distance from the surface closest to the object side of the optical system to the image surface in the direction of the optical axis of the light incident on the image surface.

[0010] The optical system according to the second aspect of the present invention includes an incident surface, a first reflection portion, and a second reflection portion, and forms an image of an object. The incident surface allows light from the object side to enter, the first reflection portion reflects the light that has passed through the incident surface, and the second reflection portion reflects the light that has been reflected by the first reflection portion. Among them, the optical system satisfies the condition of the following formula:

[0011] 10.00° < ω

[0012] Among them,

[0013] ω: The half field angle of the optical system.

[0014] The optical system of the third aspect of the present invention includes an incident surface, a first reflection portion, and a second reflection portion, and forms an image of an object. The incident surface receives light from the object side. The first reflection portion reflects the light that has passed through the incident surface. The second reflection portion reflects the light reflected by the first reflection portion. Among them, on the optical path, the medium between the first reflection portion and the second reflection portion is a transmissive member having a refractive index. On the object side of the transmissive member, on the surface where light is incident, an incident surface is formed. On the image side of the transmissive member, on the surface where the light that has passed through the incident surface is incident, a reflection surface serving as the first reflection portion is formed. On the object side of the transmissive member, on the surface where the light reflected by the first reflection portion is incident, a reflection surface serving as the second reflection portion is formed. An exit surface is formed. The exit surface is the surface on the image side of the transmissive member and receives the light reflected by the second reflection portion, and causes the light to exit from the transmissive member. When viewed from a direction orthogonal to the optical axis of the optical system, the reflection surface of the second reflection portion is disposed at a position closer to the object side than the incident surface.

[0015] The optical system of the fourth aspect of the present invention includes: a first reflection portion that reflects incident light; and a second reflection portion that reflects the light reflected by the first reflection portion. Light from an object is incident on the first reflection portion and is reflected. The light reflected by the first reflection portion is incident on the second reflection portion and is reflected, and then is reflected again by the first reflection portion. Then, the light reflected by the first reflection portion is incident on the second reflection portion again and then exits from the optical system, forming an image of the object.

[0016] The imaging device of the first aspect of the present invention includes a plurality of imaging units. The imaging unit includes: an optical system that sequentially has a first reflection surface and a second reflection surface from the object side along the optical path and forms an image of an object; and an imaging element that images the image formed by the optical system. At least two of the imaging elements are arranged in a manner different from the relative position in the optical axis direction of the optical system.

[0017] Regarding the manufacturing method of the optical system of the first aspect of the present invention, the optical system includes an incident surface, a first reflection portion, and a second reflection portion, and forms an image of an object. The incident surface receives light from the object side. The first reflection portion reflects the light that has passed through the incident surface. The second reflection portion reflects the light reflected by the first reflection portion. Among them, the optical system is arranged in a manner that satisfies the following conditions:

[0018] TL < 15.0 mm

[0019] Among them,

[0020] TL: In the direction of the optical axis of the light incident on the image surface, the distance from the surface closest to the object side of the optical system to the image surface.

[0021] A method for manufacturing an optical system according to a second aspect of the present invention, the optical system including an entrance surface, a first reflecting portion, and a second reflecting portion, and forming an image of an object, wherein the entrance surface receives light from the object side, the first reflecting portion reflects the light that has passed through the entrance surface, and the second reflecting portion reflects the light that has been reflected by the first reflecting portion, and wherein the optical system is arranged to satisfy the condition of the following formula:

[0022] 10.00° < ω

[0023] wherein,

[0024] ω: the half field angle of the optical system.

[0025] A method for manufacturing an optical system according to a third aspect of the present invention, the optical system including an entrance surface, a first reflecting portion, and a second reflecting portion, and forming an image of an object, wherein the entrance surface receives light from the object side, the first reflecting portion reflects the light that has passed through the entrance surface, and the second reflecting portion reflects the light that has been reflected by the first reflecting portion, and wherein, on the optical path, the medium between the first reflecting portion and the second reflecting portion is a transmissive member having a refractive index, on the object side of the transmissive member, on the surface where light is incident, an entrance surface is formed, on the image side of the transmissive member, on the surface where the light that has passed through the entrance surface is incident, a reflecting surface as the first reflecting portion is formed, on the object side of the transmissive member, on the surface where the light that has been reflected by the first reflecting portion is incident, a reflecting surface as the second reflecting portion is formed, an exit surface is formed, the exit surface is the image side surface of the transmissive member, and receives the light that has been reflected by the second reflecting portion, and causes the light to exit from the transmissive member, and when viewed from a direction orthogonal to the optical axis of the optical system, the reflecting surface of the second reflecting portion is arranged at a position closer to the object side than the entrance surface.

[0026] A method for manufacturing an optical system according to a fourth aspect of the present invention, the optical system including a first reflecting portion that reflects incident light and a second reflecting portion that reflects the light reflected by the first reflecting portion, and wherein the optical system is arranged such that: light from an object is incident on the first reflecting portion and is reflected, the light reflected by the first reflecting portion is incident on the second reflecting portion and is reflected and then is reflected by the first reflecting portion again, and then the light reflected by the first reflecting portion is incident on the second reflecting portion again and then exits from the optical system, forming an image of the object.

[0027] A method for manufacturing a photographing device according to a first aspect of the present invention, the photographing device including a plurality of photographing portions, the photographing portion including: an optical system that sequentially has a first reflecting surface and a second reflecting surface from the object side along the optical path and forms an image of an object; and a photographing element that photographs the image formed by the optical system, and wherein at least two of the photographing elements are arranged such that their relative positions in the optical axis direction with respect to the optical system are different. Description of the Drawings

[0028] Figure 1 It is an explanatory drawing showing a camera module, where (a) is the front view and (b) is the sectional view.

[0029] Figure 2 It is a sectional view of the optical system constituting the camera module. (a) shows the basic structure of the Schmidt-Cassegrain type, and (b) shows the structure with a lens added to (a).

[0030] Figure 3 It is a graph showing the relationship between the secondary magnification ratio and astigmatism in the optical systems of the Schmidt-Cassegrain type and the Cassegrain type.

[0031] Figure 4 It is a perspective view showing the appearance of a camera module with a multi-eye structure.

[0032] Figure 5 It is an explanatory drawing showing a camera module with a multi-eye structure. (a) is the front view, and (b) is the A-A sectional view of (a).

[0033] Figure 6 It is an explanatory drawing showing the structures of the first optical component and the second optical component.

[0034] Figure 7 It is an explanatory drawing showing the structure of the optical system block part.

[0035] Figure 8 It is an explanatory drawing for explaining the focusing mechanism.

[0036] Figure 9 It is an explanatory drawing for explaining the field of view of the camera module. (a) shows the telephoto end state, and (b) shows the wide-angle end state.

[0037] Figure 10 It is an explanatory drawing for explaining the zoom mechanism. (a) shows the side view, and (b) shows the zoom method.

[0038] Figure 11 It is an explanatory drawing showing the moving direction of the field of view of each optical system when zooming from the telephoto end state to the wide-angle end state.

[0039] Figure 12 It is an explanatory drawing for explaining the removal of stray light. (a) shows an example of stray light, and (b) shows the first structure.

[0040] Figure 13 It is an explanatory drawing showing the second structure for removing stray light.

[0041] Figure 14 It is an explanatory drawing for explaining the setting of the position of the optical axis direction of the imaging element of each unit block.

[0042] Figure 15 It is an explanatory diagram for explaining the combination with the lighting device.

[0043] Figure 16 It is an explanatory diagram showing the arrangement pattern of the camera and the lighting device.

[0044] Figure 17 It is an explanatory diagram of a multi-stage folding-back structure. (a) shows the case where each mirror is constituted by a separate component, and (b) shows the case where each of the main mirror and the sub-mirror is constituted by one component.

[0045] Figure 18 It is a schematic diagram of a camera equipped with a camera module.

[0046] Figure 19 It is a flowchart showing the manufacturing method of the camera module.

[0047] Figure 20 It is a cross-sectional view showing the lens structure of the optical system of the first embodiment.

[0048] Figure 21 It is an aberration diagram of the optical system of the first embodiment.

[0049] Figure 22 It is a cross-sectional view showing the lens structure of the optical system of the second embodiment.

[0050] Figure 23 It is an aberration diagram of the optical system of the second embodiment.

[0051] Figure 24 It is a cross-sectional view showing the lens structure of the optical system of the third embodiment.

[0052] Figure 25 It is an aberration diagram of the optical system of the third embodiment.

[0053] Figure 26 It is a cross-sectional view showing the lens structure of the optical system of the fourth embodiment.

[0054] Figure 27 It is an aberration diagram of the optical system of the fourth embodiment.

[0055] Figure 28 It is an explanatory diagram showing the structure of the optical systems of the fifth to seventh embodiments.

[0056] Figure 29 It is a cross-sectional view when the optical system is constituted by an integrated lens.

[0057] Figure 30 It is an explanatory diagram showing the structure of the optical system of the eighth embodiment.

[0058] Figure 31 These are aberration diagrams of the optical system of the eighth embodiment.

[0059] Figure 32 This is an explanatory diagram showing the structure of the optical system of the ninth embodiment.

[0060] Figure 33 These are aberration diagrams of the optical system of the ninth embodiment.

[0061] Figure 34 This is an explanatory diagram showing the structure of the optical system of the tenth embodiment.

[0062] Figure 35 These are aberration diagrams of the optical system of the tenth embodiment. Detailed Embodiments

[0063] Hereinafter, preferred embodiments will be described with reference to the accompanying drawings.

[0064] (Structure of Camera Module 10)

[0065] As Figure 1 shown, the camera module 10, which is a photographing device of the present embodiment, is composed of an optical system UL and a photographing element 14. Light from the object side is imaged by the optical system UL, and the photographed object image is photographed by the photographing element 14.

[0066] As Figure 2As shown in (a), the optical system UL is a so-called Schmidt-Cassegrain type (or, compact Schmidt-Cassegrain type), and sequentially includes, along the optical axis from the object (subject) side: a correction plate 11 as a correction component, which has a correction surface 11a that is a high-order aspherical surface and transmits light from the object; a main mirror 12 as the first reflection part, which has a concave reflecting surface (the first reflection surface 12a) facing the object side and reflects the light that has passed through the correction plate 11; and a sub-mirror 13 as the second reflection part, which is arranged on the object side in a manner opposite to the main mirror 12, has a convex reflecting surface (the second reflection surface 13a) facing the image side (the main mirror 12 side), and reflects the light reflected by the main mirror 12. Here, the optical axis of the light incident on the first reflection surface 12a coincides with the optical axis of the light reflected by the first reflection surface 12a. In addition, the optical axis of the light incident on the second reflection surface 13a coincides with the optical axis of the light reflected by the second reflection surface 13a. Further, in the central part of the main mirror 12, an opening 12b is formed in a manner that includes the optical axis of the optical system UL, and the light reflected by the sub-mirror 13 passes through this opening 12b. That is, the first reflection surface 12a has an opening 12b formed in a manner that includes the optical axis of the light incident on this first reflection surface 12a, and the second reflection surface 13a reflects light toward the opening 12b. A photographing element 14 is arranged on the image side of the main mirror 12 in a manner opposite to the opening 12b. In addition, the main mirror 12 and the sub-mirror 13 are configured to condense light from the object, and the optical system UL is configured such that the photographing element 14 is located at the focal point of the main mirror 12 and the sub-mirror 13 (the focal point of the optical system UL) (configured such that the photographing surface of the photographing element 14 substantially coincides with the image plane I of the optical system UL). As described above, the optical axis of the optical system UL sequentially passes through the correction plate 11 from the object side, is reflected by the main mirror 12 and bent, and is reflected and bent again by the sub-mirror 13. In addition, the main mirror 12 (the first reflection surface 12a) as the first reflection part 12 may be an annular shape centered on the optical axis, or may be a shape in which a rectangular or circular opening 12b is provided in a rectangular shape centered on the optical axis. In addition, the sub-mirror 13 (the second reflection surface 13a) as the second reflection part 13 may also be circular or rectangular centered on the optical axis.

[0067] In addition, regarding Figure 2The optical system UL shown in (a), although it shows the case where the object-side surface of the correction plate 11 is the correction surface 11a, the image-side surface can also be the correction surface 11a. Regarding the correction surface 11a, preferably, when the aberration deteriorates due to the reflecting surfaces (the first reflecting surface 12a and the second reflecting surface 13a), the aberration is corrected, and it is also possible to correct the types of aberration that cannot be completely corrected by the reflecting surfaces and the high-order aberration that cannot be completely corrected by the reflecting surfaces. The correction surface 11a is preferably a high-order aspherical surface, but it can be a spherical surface or an aspherical surface rather than a flat surface. In addition, although the surface of the correction plate 11 where the correction surface 11a is not formed is a flat surface in the present embodiment, it can also be a spherical surface or a free-form surface.

[0068] (Optical system UL)

[0069] As described above, the optical system UL is constituted by a reflective optical system. Here, even if at least one or both of the first reflecting surface 12a of the main mirror 12 and the second reflecting surface 13a of the secondary mirror 13 are formed by spherical surfaces, the aberration generated by the main mirror 12 and the secondary mirror 13 can be corrected by the object-side surface of the correction plate 11, that is, a high-order aspherical surface (for example, a fourth-order surface). Therefore, an image without coma, astigmatism, and distortion can be obtained as a whole. Therefore, at least one of the first reflecting surface 12a of the main mirror 12 and the second reflecting surface 13a of the secondary mirror 13 is preferably a spherical surface, and more preferably, both the first reflecting surface 12a and the second reflecting surface 13a are spherical surfaces. By making at least one of the first reflecting surface 12a and the second reflecting surface 13a a spherical surface, it is easy to manufacture the optical system UL.

[0070] In addition, as Figure 2 shown in (b), a refractive optical system (for example, a lens) 15 that refracts the light passing through the opening 12b of the main mirror 12 can also be provided in the optical system UL. In addition, the optical system UL can also be a Cassegrain-type optical system that does not have the correction plate 11. In addition, it is preferable that the optical axes of all the optical elements included in the optical system UL coincide. At least, preferably, the optical axis of the main mirror 12 and the optical axis of the secondary mirror 13 are the same except that the directions of the light passing through are opposite.

[0071] Regarding the camera module 10 of the present embodiment, by making the optical system UL a catadioptric optical system (a reflective optical system of the Cassegrain type, the Schmidt-Cassegrain type, or the compact Schmidt-Cassegrain type) using the reflecting surfaces as described above, compared with the case where the optical system is constituted by an optical system that does not use reflecting surfaces, the length of the optical system (from the most object-side surface ( Figure 2In the case of (a), the physical distance from the object side surface (correction surface 11a) of the correction plate 11 to the image surface (the imaging surface of the imaging element 14) becomes 1 / 2 to 1 / 3.

[0072] In addition, in the optical system UL of the present embodiment, the medium between the first reflection surface 12a of the main mirror 12 and the second reflection surface 13a of the sub-mirror 13 is air. When configured as described above, it is possible to easily manufacture the camera module 10 including the optical system UL. In addition, when not performing photography, the correction plate 11 and the sub-mirror 13 can be moved (so-called retracted) toward the main mirror 12 side and stored, so that the camera module 10 can be miniaturized, and at least a part thereof can be accommodated in an optical device such as a camera.

[0073] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (1).

[0074] TL < 15.0 mm (1)

[0075] Herein,

[0076] TL: The distance from the most object-side surface to the image surface I of the optical system UL in the direction of the optical axis incident on the image surface I

[0077] The conditional expression (1) shows an appropriate range of the length in the optical axis direction of the optical system UL when the optical system UL is configured by a Schmidt-Cassegrain (or compact Schmidt-Cassegrain) type reflection optical system. In addition, in order to reliably obtain the effect of the conditional expression (1), it is preferable that the upper limit value of the conditional expression (1) is 14.0 mm, 13.0 mm, and more preferably 12.0 mm. In addition, in order to reliably obtain the effect of the conditional expression (1), it is preferable that the lower limit value of the conditional expression (1) is 6 mm. In addition, when having Figure 2 the correction plate 11 shown, the most object-side surface of the optical system UL becomes the correction surface 11a.

[0078] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (2).

[0079] 10.00° < ω (2)

[0080] Herein,

[0081] ω: The half field angle of the optical system UL

[0082] Conditional expression (2) shows the appropriate range of the half field angle of the optical system UL when the reflective optical system in the Schmidt-Cassegrain (or compact Schmidt-Cassegrain) method constitutes the optical system UL. In addition, in order to reliably obtain the effect of this conditional expression (2), preferably, the lower limit value of the conditional expression (2) is 8.00°, 6.00°, 5.00°, 4.00°, 3.50°, 3.00°, 2.50°, 2.00°, and more preferably 1.50°.

[0083] In addition, when the optical system UL in the present embodiment is in the compact Schmidt-Cassegrain method, the thickness ΔL of the correction plate 11 is expressed by the following formula (a). In addition, formula (a) was published in APPLIED OPTICS Vol.13, No.8, August 1974.

[0084] ΔL = [(h / r) 4 -1.5(h / r) 2 r / {256(n - 1)P′ 3}+k (a)

[0085] Wherein,

[0086] P′ = P1 / G 1 / 3

[0087] P1: F value of the primary mirror 12

[0088] G: Ratio of the calculated depth of the correction plate 11

[0089] h: Height in the direction perpendicular to the optical axis

[0090] r: Correction radius (curvature radius) of the correction plate 11

[0091] n: Refractive index of the medium constituting the correction plate 11

[0092] k: Central thickness of the correction plate 11

[0093] In addition, in the optical system UL of the present embodiment, a transmission component that transmits light from an object can also be appropriately set at a position on the optical path. By setting the transmission component, it is possible to form an aspherical surface or the like on the transmission component to correct aberration. The aspherical surface of the transmission component (including the correction surface 11a of the correction plate 11) preferably has at least one inflection point from the optical axis toward the periphery.

[0094] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (3).

[0095] -0.1 < f / fa < 0.1 (3)

[0096] Wherein,​

[0097] fa: Focal length of the correction plane 11a

[0098] f: Focal length of the entire optical system UL

[0099] The conditional expression (3) shows the appropriate range of the ratio of the focal length of the entire optical system UL to the correction plane 11a when the reflective optical system in the Schmidt-Cassegrain (or compact Schmidt-Cassegrain) configuration constitutes the optical system UL. Additionally, in order to reliably obtain the effect of the conditional expression (3), it is preferable that the lower limit value of the conditional expression (3) be -0.05, -0.02, and more preferably 0.00. Also, in order to reliably obtain the effect of the conditional expression (3), it is preferable that the upper limit value of the conditional expression (3) be 0.09, 0.08, 0.07, 0.06, and more preferably 0.05.

[0100] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (4).

[0101] -0.1 < f / fb < 0.1 (4)

[0102] wherein,

[0103] fb: Focal length of the correction plate 11

[0104] f: Focal length of the entire optical system UL

[0105] The conditional expression (4) shows the appropriate range of the ratio of the focal length of the entire optical system UL to the focal length of the correction plate 11 when the reflective optical system in the Schmidt-Cassegrain (or compact Schmidt-Cassegrain) configuration constitutes the optical system UL. Additionally, in order to reliably obtain the effect of the conditional expression (4), it is preferable that the lower limit value of the conditional expression (4) be -0.05, -0.02, and more preferably 0.00. Also, in order to reliably obtain the effect of the conditional expression (4), it is preferable that the upper limit value of the conditional expression (4) be 0.09, 0.08, 0.07, 0.06, and more preferably 0.05.

[0106] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (5).

[0107] 3.0 < M < 8.0 (5)

[0108] wherein,

[0109] M = f / f1

[0110] f: Focal length of the entire optical system UL

[0111] f1: Focal length of the main mirror 12

[0112] Conditional expression (5) shows the appropriate range of the secondary magnification ratio M of the optical system UL when the reflective optical system in the Schmidt-Cassegrain (or compact Schmidt-Cassegrain) configuration forms the optical system UL.

[0113] Figure 3 Shows the astigmatism with respect to the secondary magnification ratio M in the reflective optical systems of the Cassegrain configuration and the Schmidt-Cassegrain configuration. As can be seen from this Figure 3 It can be understood that when the reflective optical system in the Schmidt-Cassegrain (or compact Schmidt-Cassegrain) configuration forms the optical system UL, by setting the secondary magnification ratio M to 5.6, the astigmatism can be made zero. Therefore, by making the optical system UL satisfy conditional expression (5), the generation of astigmatism can be suppressed, and a good image can be obtained. In addition, in order to reliably obtain the effect of this conditional expression (5), preferably, the lower limit value of conditional expression (5) is 3.5, more preferably 4.0, 4.5, 5.0. In addition, in order to reliably obtain the effect of this conditional expression (5), preferably, the upper limit value of conditional expression (5) is 7.5, more preferably 7.0, 6.5, 6.0.

[0114] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (6).

[0115] f < 500 mm (6)

[0116] wherein

[0117] f: Focal length of the entire system of the optical system UL

[0118] Conditional expression (6) shows the appropriate range of the focal length of the entire system of the optical system UL when the reflective optical system in the Schmidt-Cassegrain (or compact Schmidt-Cassegrain) configuration forms the optical system UL. In addition, in order to reliably obtain the effect of this conditional expression (6), preferably, the lower limit value of conditional expression (6) is 0.1 mm, more preferably 1 mm, 5 mm, 10 mm, 20 mm. In addition, in order to reliably obtain the effect of this conditional expression (6), preferably, the upper limit value of conditional expression (6) is 380 mm, more preferably 280 mm, 230 mm, 190 mm, 140 mm, 90 mm, 70 mm, 55 mm, 45 mm.

[0119] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (7).

[0120] 0.4 < RL / TL < 1.2 (7)

[0121] wherein

[0122] RL: The distance on the optical axis between the first reflecting portion and the second reflecting portion in the direction of the optical axis of the optical system UL

[0123] TL: The distance from the surface closest to the object side of the optical system to the image plane in the direction of the optical axis of the light incident on the image plane

[0124] Conditional expression (7) shows an appropriate range of the ratio of the distance from the surface closest to the object side of the optical system UL to the image plane to the distance between the reflecting surfaces. In addition, in order to reliably obtain the effect of conditional expression (7), preferably, the upper limit value of conditional expression (7) is 1.0, 0.9, and more preferably 0.85. In addition, in order to reliably obtain the effect of conditional expression (7), preferably, the lower limit value of conditional expression (7) is 0.6, 0.7.

[0125] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (8).

[0126] 0.5 < D1 / RL < 2.0 (8)

[0127] Wherein,

[0128] D1: The outer diameter of the first reflecting surface

[0129] RL: The distance on the optical axis between the first reflecting portion and the second reflecting portion in the direction of the optical axis of the optical system UL

[0130] Conditional expression (8) shows an appropriate range of the ratio of the lengths of the optical system UL in the direction of the optical axis and in the direction orthogonal to the optical axis. Here, regarding the outer diameter of the first reflecting surface, it is the diameter when the first reflecting surface is circular, and it is the maximum outer diameter when the first reflecting surface is rectangular. In addition, in order to reliably obtain the effect of conditional expression (8), preferably, the upper limit value of conditional expression (8) is 1.7, 1.5, and more preferably 1.3. In addition, in order to reliably obtain the effect of conditional expression (8), preferably, the lower limit value of conditional expression (8) is 0.7, 0.8, and more preferably 0.85.

[0131] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (9).

[0132] 1.0 < D1 / D2 < 6.0 (9)

[0133] Wherein,

[0134] D1: The outer diameter of the first reflecting surface

[0135] D2: The outer diameter of the second reflecting surface

[0136] Conditional expression (9) shows an appropriate range of the ratio of the outer diameters of the reflecting surfaces to each other. Here, regarding the outer diameter of the first reflecting surface or the outer diameter of the second reflecting surface, it is the diameter when the reflecting surface is circular, and it is the maximum outer diameter when the reflecting surface is rectangular. Further, in order to reliably obtain the effect of this conditional expression (9), it is preferable that the upper limit value of the conditional expression (9) is 5.0, 5.5, and more preferably 3.0. Further, in order to reliably obtain the effect of this conditional expression (9), it is preferable that the lower limit value of the conditional expression (9) is 1.3, 1.5, and more preferably 3.5.

[0137] Further, the optical system UL of the present embodiment preferably satisfies the following conditional expression (10).

[0138] 5.0 < D0 / Y < 15.0 (10)

[0139] Wherein,

[0140] D0: The outer diameter of the incident surface of the optical system UL closest to the object side

[0141] Y: The maximum image height of the imaging element 14

[0142] Conditional expression (10) shows an appropriate range of the ratio of the outer diameter of the incident surface to the maximum image height of the imaging element 14. Here, regarding the outer diameter of the incident surface, it is the diameter when the incident surface is circular, and it is the maximum outer diameter when the incident surface is rectangular. Further, in order to reliably obtain the effect of this conditional expression (10), it is preferable that the upper limit value of the conditional expression (10) is 14.5, 14.0, and more preferably 9.0. Further, in order to reliably obtain the effect of this conditional expression (10), it is preferable that the lower limit value of the conditional expression (10) is 6.0, 7.0, and more preferably 10.0.

[0143] (Regarding the multi-eye structure of the camera module 10)

[0144] In Figure 1 it has been described that the camera module 10 is constituted by the optical system UL and the imaging element 14 as a set of photographing units, but as shown in Figure 4 and Figure 5 it may also be the camera module 1 as a multi-eye structure photographing device in which a plurality of the above-described camera modules 10 are two-dimensionally arranged. Further, in the following description, the above-described camera module 10 in the multi-eye structure is referred to as "unit block 10". Further, in the following description related to the multi-eye structure, as shown in Figure 4As shown, although the case where the camera module 1 is composed of a total of nine (hereinafter referred to as "3×3") unit blocks 10 arranged in three rows and three columns is described, the same effect can be obtained even if it is composed of two or more unit blocks 10. The number of unit blocks 10 included in one row and the number of unit blocks 10 included in one column may also be different. Hereinafter, when synthesizing the images obtained from the imaging elements 14 constituting the unit block 10, by making the number of unit blocks 10 included in one row the same as the number of unit blocks 10 included in one column, an image with the same resolution can be generated in the vertical and horizontal directions. In addition, the optical systems UL of the plurality of unit blocks 10 constituting the camera module 1 are arranged such that their optical axes are substantially parallel to each other. In addition, the imaging elements 14 of the plurality of unit blocks 10 are arranged on a plane orthogonal to the optical axis, and are two-dimensionally arranged in the X-axis direction orthogonal to the optical axis and the Y-axis direction orthogonal to the X-axis and the optical axis.

[0145] For the camera module 1 of the present embodiment, compared with the case where the optical system UL of the unit block 10 is a catadioptric optical system (a reflective optical system such as a Cassegrain type, a Schmidt-Cassegrain type, or a compact Schmidt-Cassegrain type) as described above, and the length of the optical system is composed of a refractive optical system (the physical distance from the most object-side surface to the image surface), it can be 1 / 2 to 1 / 3. Moreover, the camera module 1 of the present embodiment includes a plurality of unit blocks 10, and by synthesizing the images obtained by the imaging elements 14 of each unit block 10, a high-resolution image with a resolution higher than that of each imaging element 14 can be obtained. Therefore, the size of the imaging element 14 can be reduced (even if each imaging element 14 is reduced and its resolution is lowered, a high-resolution image can be obtained by synthesizing the images). By miniaturizing the imaging element 14, the focal length of the optical system UL of the unit block 10 can be shortened. Therefore, by adopting a catadioptric optical system and the image synthesis effect based on a plurality of unit blocks 10, the overall length of the camera module 1 of the present embodiment can be made 1 / 4 or less compared with a camera module composed of one unit block 10 using a refractive optical system with the same resolution.

[0146] (Assembly structure of camera module 1)

[0147] Next, the assembly structure of the camera module 1 of the present embodiment will be described. In addition, although the assembly structure of the multi-eye camera module 1 is described here ( Figure 4 and Figure 5 ), the same applies to the case of a single-eye camera module 10 ( Figure 1 ).

[0148] As shown in Figure 4 and Figure 5As shown in the figure, the camera module 1 of the present embodiment includes: a first optical component 110 formed with a correction plate 11 (correction component) and a secondary mirror 13 (second reflection portion); a second optical component 120 formed with a primary mirror 12 (first reflection portion); a partition member 130 disposed between the first optical component 110 and the second optical component 120, provided at the boundary between the unit blocks 10 to prevent light from entering adjacent unit blocks 10; and a photographing component 140 configured with a photographing element 14.

[0149] Regarding the first optical component 110, as Figure 6 (a) shows, on the upper surface (the surface on the object side in the optical system UL) of a parallel plane glass plate 111 formed of a light-transmitting medium, a plurality of correction plates 11 are formed by imprinting a polymer as the light-transmitting medium (in Figure 4 the example, 9 correction plates 11 of 3×3 are formed). In addition, the first optical component 110 can also be made by cutting out from a substrate material formed with a correction plate 11 by imprinting or the like. In addition, on the lower surface (the surface on the image side in the optical system UL) of the parallel plane glass plate 111, a reflection component for reflecting light is mask-coated, and a plurality of secondary mirrors 13 are formed (in Figure 4 the example, 9 secondary mirrors 13 of 3×3 are formed). As described above, by forming a plurality of correction plates 11 and a plurality of secondary mirrors 13 on both sides of a single parallel plane glass 111, it is possible to manufacture, for example, by one process Figure 4 each correction plate 11 and secondary mirror 13 of the 3×3 nine unit blocks 10 shown.

[0150] In addition, although Figure 6 (a) shows a case where a correction surface is formed on the surface on the object side of the correction plate 11, a correction surface can also be formed on the surface on the image side of the correction plate 11. When a correction surface is formed on the surface on the image side of the correction plate 11, a correction surface can be formed together with the secondary mirror 13 formed on this surface, so that the manufacturing process can be made simpler.

[0151] Regarding the second optical component 120, as Figure 6 (b) shows, on the upper surface of a parallel plane glass plate 121 formed of a light-transmitting medium, a reflection component for reflecting light is mask-coated, and a plurality of primary mirrors 12 are formed ( Figure 4 in the example, 9 primary mirrors 12 of 3×3 are formed). In addition, by forming the parallel plane glass plate 121 with a light-transmitting medium, an opening 12b can be formed in each unit block 10 by forming a portion where the primary mirror 12 is not mask-coated. As described above, by forming the primary mirror 12 on a single surface (the surface on the object side in the optical system UL) of a single parallel plane glass 121, it is possible to manufacture, for example, by one process Figure 4Each main mirror 12 of the 3×3 unit block 10 shown.

[0152] In addition, as Figure 2 (b) shows, when a refractive optical system 15 such as a lens is provided in the optical system UL, a lens surface capable of refracting light can also be formed on the parallel plane glass plate 121.

[0153] As Figure 7 shown, the partition member 130 is formed by partitioning the optical partition lattice of the optical system UL of the unit block 10. The first optical member 110 is disposed on the object side of the partition member 130, and the second optical member 120 is disposed on the image side of the partition member 130. By fixing the first optical member 110 on the object side of the partition member 130 and fixing the second optical member 120 on the image side of the partition member 130, the partition member 130 can prevent the light of the optical system UL of the unit block 10 from entering the adjacent unit block 10 while also performing the positioning in the optical axis direction between the first optical member 110 and the second optical member 120. In addition, in the following description, the integrally formed first optical member 110, second optical member 120, and partition member 130 are referred to as the optical system block portion 100. The optical system block portion 100 is composed of a plurality of unit blocks 10. The partition of the partition member 130 is made of a material having a light-blocking effect such as metal or polymer, and the thickness is about 0.5 to 1.0 mm. In addition, regarding the inside of the partition, preferably, in order to optically block each unit block 10 from the outside and prevent reflection, an anti-reflection coating (for example, painted black) is applied. In addition, the inside of the partition may be a cavity (in a state filled with air), or may be filled with a medium that transmits light.

[0154] As Figure 4 and Figure 5 (b) shows, in the photographing member 140, a plurality of photographing elements 14 are arranged at positions corresponding to the respective optical systems UL. As will be described later, the position of the optical system block portion 100 in the direction along the optical axis with respect to the photographing member 140 can be fixed or variable.

[0155] The first optical component 110, the second optical component 120, the partition component 130, and the imaging component 140 may also be integrated by adjusting the positions of the components relative to each other after they are separately manufactured. Additionally, at least some of the first optical component 110, the second optical component 120, the partition component 130, and the imaging component 140 may be continuously manufactured. For example, a plurality of imaging elements 14 may be disposed on a single board component, and the second optical component 120, the partition component 130, and the first optical component 110 may be sequentially formed thereon. Alternatively, the second optical component 120, the partition component 130, and the first optical component 110 may be sequentially formed, and then combined with the imaging component 140 after the optical system block portion 100 is manufactured.

[0156] In addition, the partition component 130 may be omitted, and a component that positions the first optical component 110 and the second optical component 120 in the optical axis direction may be used instead of the partition component 130.

[0157] Alternatively, the optical block portion 100 may be constituted by using transmission components formed of a medium that transmits light. In this case, two transmission components may be used. A correction surface 11a and a second reflection surface 13a may be formed on the first transmission component, and a first reflection surface 12a may be formed on the second transmission component disposed with an air gap from the first transmission component. Alternatively, when an integral transmission component is used, a correction surface 11a and a second reflection surface 13a may be formed on the object-side surface of the transmission component, and a first reflection surface 12a may be formed on the image-side surface of the transmission component. The type of medium included in the transmission component may be one or more. Here, different types of media mean that at least one of the refractive index and the Abbe number is different. In the case of multiple types, the transmission component is constituted by a portion formed of a first medium and a portion formed of a second medium. The boundary between the portion formed of the first medium and the portion formed of the second medium is formed along a plane perpendicular to the optical axis and is a plane or a spherical surface.

[0158] (Regarding Focus)

[0159] Regarding the closest distance of the monocular camera module 10 of the present embodiment (although the monocular camera module 10 is described here, it is the same for the multi-eye camera module 1), a distance that can achieve a magnification of about 50 to 100 times can be determined as a reference. In other words, the closest distance of the camera module 10 of the present embodiment varies according to the focal length. In Table 1 below, the relationship between the magnification and the telescopic amount of the optical system UL from infinity to the closest distance is shown when the camera module 10 of the present embodiment corresponds to a telephoto optical system equivalent to 300 mm, 500 mm, and 1000 mm when the focal length is converted to a 35 mm camera. In addition, as described above, since the optical system UL is integrally formed as the optical system block unit 100, the first optical component 110, the partition member 130, and the second optical component 120 are integrally moved in the object direction so as to be separated from the imaging element 14. In the case of the multi-eye camera module 1, a plurality of (nine in the present embodiment) correction plates 11 and a plurality of (nine in the present embodiment) sub-mirrors 13 are also integrally formed, a plurality of (nine in the present embodiment) main mirrors 12 are also integrally formed, and the partition members separating the respective unit blocks 10 are also integrally formed. Therefore, a plurality of (nine in the present embodiment) optical systems UL can be integrally moved.

[0160] (Table 1) Relationship between magnification and telescopic amount of optical system from infinity to closest distance

[0161]

[0162] In addition, in Table 2 below, the relationship between the magnification and the closest distance is shown when the camera module 10 of the present embodiment corresponds to a telephoto optical system equivalent to 300 mm, 500 mm, and 1000 mm when the focal length is converted to a 35 mm camera.

[0163] (Table 2) Relationship between magnification and closest distance

[0164]

[0165] Here, in the case of the multi-eye camera module 1 composed of a plurality of optical systems UL, the focus offset amount can be calculated using the images obtained from the imaging elements 14 of the unit blocks 10 having the optical systems UL. Since the multi-eye camera module 1 of the present embodiment has nine unit blocks 10 of 3×3, when the distance between the unit blocks 10 is 6 mm, considering the S / N ratio, the effective baseline length is the square root of 9 times, that is, about 20 mm.

[0166] Based on the above, focusing of the camera module 10 of the present embodiment is performed by adopting an overall telescopic method and moving the optical system block portion 100 (the first optical component 110, the second optical component 120, and the partition wall component 130) integrally toward the object side. That is, when focusing, the distance between the optical system block portion 100 and the imaging component 140 is changed. For example, as Figure 8 shown, as a focusing mechanism 150, by mounting a pin 151 on the outer peripheral surface of the partition wall component 130 and using a wedge member 152 mounted on a ball screw 153 driven by a driving portion 154 such as a motor to press the pin 151, the optical system block portion 100 of the camera module 1, that is, the entire optical system UL, can be moved toward the object side ( Figure 8 the arrow direction in ), thereby performing focusing. The moving amount (telescopic amount) of the entire optical system UL of the camera module 10 is equal to the telescopic amount up to the closest distance shown in Table 1. Therefore, in a 35 mm camera, in the camera module 1 equivalent to 300 mm and 50 times, the maximum telescopic amount becomes 0.4 mm (distance 1.0 m shown in Table 2), and in the camera module 1 equivalent to 1000 mm and 50 times, the maximum telescopic amount becomes 1.3 mm (distance 3.3 m). In addition, focusing can also be performed by moving at least a part of the imaging element 14 and the optical system UL in the optical axis direction.

[0167] (Regarding zooming)

[0168] The multi-eye structured camera module 1 of the present embodiment is composed of a plurality of unit blocks 10 and is arranged such that the optical axes of the optical systems UL constituting each unit block 10 are substantially parallel to each other. Therefore, the fields of view of the plurality of optical systems UL almost overlap ( Figure 9 the field of view fvt shown in (a)). On the other hand, since the multi-eye structured camera module 1 of the present embodiment is composed of a plurality of unit blocks 10, by bending the optical axes of the optical systems UL constituting each unit block 10, the fields of view of the respective optical systems UL do not overlap, and the overall field of view of the camera module 1 can be expanded. For example, as Figure 9 (b) shows, without changing the optical axis of the optical system UL of the central unit block 10 in the 3×3 optical systems UL constituting the 3×3 unit blocks 10, the optical axes of the optical systems UL of the peripheral 8 unit blocks 10 are bent in the direction where their fields of view do not overlap, thereby enabling a wide overall field of view. For example, when there are 3×3 unit blocks 10, as the Figure 9 field of view fvw in (b) shows, the field of view fvt can become 3 times.

[0169] As Figure 10 (a) shows, as a specific zooming method, an objective lens-shaped prism block (a deflection optical system as a field prism) 160 is arranged on the object side of the optical system block portion 100. AsFigure 11 As shown, the prism block 160 is configured as a parallel plate with respect to the central optical system ULc (i.e., it does not bend the optical axis of the central optical system ULc), and the optical axes of the optical systems disposed around the central optical system ULc are configured to be incident after bending outward. Specifically, the optical axes of the optical systems ULu and ULd in the vertical direction (vertically adjacent) are bent in the vertical direction, the optical axes of the optical systems ULl and ULr in the horizontal direction (horizontally adjacent) are bent in the horizontal direction, and the optical axes of the optical systems ULul, Ulur, ULdl, and ULdr in the inclined direction are bent in the inclined direction (the diagonal direction of the rectangular field of view). Figure 11 The bending direction is shown by arrows for each optical system UL.

[0170] In Table 3 below, when the refractive index of the substrate (medium) of the prism block 160 is 1.5, the relationship of the angle θ between the surface of the prism block 160 facing the peripheral optical system UL and the surface of the central optical system UL is shown Figure 10 (a). In addition, this Table 3 shows that when the focal length of the multi-eye structured camera module 1 of the present embodiment in terms of a 35 mm camera corresponds to focal lengths of 300 mm, 500 mm, and 1000 m, as Figure 9 (b) shows, the angles θ for horizontal and vertical adjacencies when the fields of view of the respective optical systems UL do not overlap and there is no gap (i.e., a state where nine fields of view are in close contact).

[0171] (Table 3) Angles of the prism block

[0172]

[0173] As can be seen from Table 3, for example, when the multi-eye structured camera module 1 of the present embodiment is converted to a 35 mm camera and corresponds to 300 mm, for the prism of the central optical system UL, a prism block 160 is installed such that the angle θ of the horizontally adjacent prism is 13.3° and the angle θ of the vertically adjacent prism is 9.1°. As a result, the field of view becomes three times, so the focal length becomes 1 / 3, and it can be zoomed to correspond to 100 mm. Similarly, by installing a prism block 160 composed of angles of 6.7° and 4.6° for horizontal and vertical adjacencies, which are half of the above angles, it can be zoomed to correspond to 200 mm.

[0174] For example, as Figure 10As shown in Fig. (b), on the parallel plane glass plate 161 formed of a medium that transmits light, a region 160a where the prism block 160 is not formed, a region 160b where the prism blocks 160 with horizontal adjacent and vertical adjacent angles θ of 6.7° and 4.6° are formed, and a region 160c where the prism blocks 160 with horizontal adjacent and vertical adjacent angles θ of 13.3° and 9.1° are formed are formed. When the above-mentioned region 160a is selected by sliding the parallel plane glass plate 161 relative to the optical system block portion 100, the focal length of the camera module 1 becomes 300 mm when converted to a 35 mm camera. When the region 160b is selected, it becomes 200 mm when converted to a 35 mm camera. When the region 160c is selected, it becomes 100 mm when converted to a 35 mm camera. Therefore, stepped zooming can be achieved.

[0175] In addition, if a liquid crystal element is used as the prism block 160, the angle of the bent optical axis can be continuously changed, and continuous zooming can be achieved. Specifically, a liquid crystal element is arranged for each unit block 10 (optical system UL), configured to deflect light in the Figure 11 direction shown, and by changing the voltage applied to the liquid crystal element, the prism amount is changed. In addition, since the liquid crystal element corresponds to only one polarization direction, it is necessary to stack the same liquid crystal elements with the alignment changed, or stack the same liquid crystal elements with a 1 / 2 wavelength plate interposed therebetween.

[0176] (Regarding the removal of stray light)

[0177] As Figure 12 shown by the light ray L in Fig. (a), the light ray that is obliquely incident on the correction plate 11 of the optical system UL sometimes passes through the opening 12b of the main mirror 12 and directly enters the imaging element 14 to become stray light. As a method for removing such stray light, the following two structures will be described.

[0178] - The first structure -

[0179] As Figure 12 shown in Fig. (b), for the first structure for removing stray light, a prevention part 19 that combines a first polarizing plate 16 as a first polarization component, a second polarizing plate 18 as a second polarization component, and a wavelength film 17 as a polarization direction rotation component is used. The first polarizing plate 16 is arranged on the object side of the correction plate 11, and is configured such that only the light that has passed through the first polarizing plate 16 enters the correction plate 11. Here, since the first polarizing plate 16 has the function of passing light polarized in a predetermined direction, the light that passes through the first polarizing plate 16 and enters the correction plate 11 becomes light with a predetermined polarization direction.

[0180] The wavelength film 17 is formed on the second reflecting surface 13a of the secondary mirror 13. The wavelength film 17 has a function of rotating the polarization direction of the transmitted light by 45°. That is, the wavelength film 17 functions as a wave plate (λ / 4 plate). Therefore, the light that has passed through the correction plate 11 and is reflected by the first reflecting surface 12a of the primary mirror 12 passes through the wavelength film 17 and the polarization direction is rotated by 45°, and is reflected by the second reflecting surface 13a of the secondary mirror 13. And, the light reflected by the second reflecting surface 13a passes through the wavelength film 17 again and the polarization direction is rotated by 45°. Therefore, the light emitted from the wavelength film 17 is in a state where its polarization direction is rotated by 90° with respect to the light before incidence. In addition, the wavelength film 17 may have a structure that rotates the polarization direction of the incident light and the emitted light.

[0181] The second polarizing plate 18 is disposed between the opening 12b of the primary mirror 12 and the imaging element 14. The second polarizing plate 18 also has a function of passing light polarized in a predetermined direction, similar to the first polarizing plate 16, and is disposed in a state where the polarization direction of the light passing through the second polarizing plate 18 is orthogonal to the polarization direction of the light passing through the first polarizing plate 16 (rotated by 90°). In addition, the second polarizing plate 18 may be mounted on the opening 12b of the primary mirror 12, or the second polarizing plate 18 may be formed on the surface of the optical component (second optical component 120) constituting the opening 12b.

[0182] As described above, the polarization direction of the light that has passed through the first polarizing plate 16 is rotated by 90° by the wavelength film 17 before being incident on the second polarizing plate 18, so it is consistent with the polarization direction that can pass through the second wave plate 18. That is, the light passing through the first polarizing plate 16, the correction plate 11, the primary mirror 12, the wavelength film 17, the secondary mirror 13, and the wavelength film 17 in this order can pass through the second wave plate 18 and be incident on the imaging element 14. On the other hand, the light that has passed through the first polarizing plate 16 and the correction plate 11 and wants to pass through the opening 12b without being reflected by the primary mirror 12 (for example, Figure 12 (a) the light ray L) is the light with the polarization direction when it has passed through the first polarizing plate 16, so it is offset by 90° from the polarization direction of the light passing through the second polarizing plate 18 and cannot pass through the second polarizing plate 18 and cannot be incident on the imaging element 14. Therefore, according to this first structure, the prevention unit 19 prevents light with a number of reflections of the first reflecting portion (primary mirror 12) and the second reflecting portion (secondary mirror 13) other than a predetermined number from being incident on the imaging element 14. Here, the light with a number of reflections of the first reflecting portion and the second reflecting portion other than a predetermined number, for example, in Figure 12 the example, refers to the light with a number of reflections of the first reflecting portion and the second reflecting portion other than 1 time, that is, the light with a number of reflections of the first reflecting portion and the second reflecting portion of 0 times or 2 times or more. In addition, in Figure 17In the example, it refers to light with a number of reflections by the first reflecting portion and the second reflecting portion other than 2, that is, light with a number of reflections by the first reflecting portion and the second reflecting portion of 0, 1, or 3 or more. Therefore, it is also possible to effectively remove stray light (light ray L) that passes through the opening portion 12b without being reflected by both the main reflecting mirror 12 and the sub-reflecting mirror 13 (number of reflections is 0).

[0183] In addition, in the case of the multi-eye structured camera module 1 of the present embodiment, as Figure 5 (b) etc. show, a plurality of imaging elements 14 are arranged. Therefore, the polarization direction of the light transmitted through the first polarizing plate 16 and the second polarizing plate 18 is preferably the same as the direction in which the imaging elements 14 are arranged.

[0184] In addition, according to the above structure, the polarization direction of the light passing through the first polarizing plate 16 and the second polarizing plate 18 is in one direction and fixed. At this time, for example, when the polarization direction of the light reflected by the second reflecting surface 13a is different from the polarization direction of the light passing through the first polarizing plate 16, an image based on this light cannot be captured. Therefore, it is preferably configured such that the first polarizing plate 16 and the second polarizing plate 18 can be mechanically rotated to rotate the polarization direction of the light that can pass through the first polarizing plate 16 and the second polarizing plate 18. At this time, it may also be configured such that the first polarizing plate 16 and the second polarizing plate 18 are constituted by liquid crystal polarizing plates, so that the polarization direction of the light that can pass through the first polarizing plate 16 and the second polarizing plate 18 can be electronically rotated. In addition, when the camera modules 1 and 10 of the present embodiment are mounted on, for example, a drone or a vehicle, it may also be configured such that the polarization direction of the first polarizing plate 16 and the second polarizing plate 18 can be rotated according to the state (flight / driving direction or inclination) of the mounted drone or vehicle.

[0185] In addition, in the present embodiment, the first polarizing plate 16 only needs to be arranged on the optical path on the object side with respect to the main reflecting mirror 12, and it is better to be arranged on the object side with respect to the correction plate 11. In addition, in the present embodiment, the second polarizing plate 18 only needs to be arranged on the optical path on the image side with respect to the sub-reflecting mirror 13, and it is better to be arranged on the image side with respect to the main reflecting mirror 12. In addition, the wavelength film 17 only needs to be arranged on the optical path between the first polarizing plate 16 and the second polarizing plate 18, and it is better to be formed on the reflecting surface of the main reflecting mirror 12 or the sub-reflecting mirror 13.

[0186] In addition, in the case of the first structure, light that enters the optical system UL of the camera modules 1 and 10 and is outside the polarization direction that can pass through the first polarizing plate 16 does not contribute to imaging. Therefore, in addition to the above-described polarization function, the first polarizing plate 16 also has a solar cell function of converting light in a polarization direction that cannot pass through into electricity, so that the light incident on the optical system UL can be effectively utilized. The electricity converted from light by the first polarizing plate 16 is used by the control unit 20 described later, for example, to generate an image from the imaging element 14.

[0187] In addition, the solar cell that supplies the power for operating the camera modules 1 and 10 may be provided not only as the first polarizing plate 16, but also, for example, at a position on the object side surface of the correction plate 11 where the sub-reflector 13 is disposed on the back side. As can be seen from Figure 1 and the like, light cannot pass through the portion of the correction plate 11 where the sub-reflector 13 is disposed (which does not contribute to image formation), so the space on the object side of the correction plate 11 can be effectively utilized as a placement location for the solar cell. Similarly, a solar cell may be disposed in a portion of the object side surface of the correction plate 11 through which light that does not contribute to image formation passes (for example, the peripheral portion of the optical system UL).

[0188] -Second Structure-

[0189] The second structure for removing stray light is a structure in which the shielding portion 19 has a light-shielding property. For example, as Figure 13 shown, in the optical axis direction of the light incident on the main reflector 12, the shielding portion 19 includes a first light-shielding member 19a and a second light-shielding member 19b disposed between the main reflector 12 and the sub-reflector 13.

[0190] The first light-shielding member 19a separates the optical path through which light that passes through the correction plate 11, enters the main reflector 12, is reflected by the main reflector 12, and is then guided to the sub-reflector 13, and the optical path through which light that is reflected by the sub-reflector 13 and is guided to the opening 12b passes. The first light-shielding member 19a is disposed on the optical axis side of the light reflected by the main reflector 12, and is formed to surround the optical axis of the optical system UL when viewed from the optical axis direction. As Figure 13As shown, the first light-shielding member 19a is a cylindrical member that is disposed at the boundary between the reflecting surface 12a of the main reflector 12 and the opening 12b (the second region formed so as to surround the first reflecting portion) so as to surround the opening 12b (disposed at the inner peripheral portion of the first reflecting portion). The first light-shielding member 19a is formed to project from the surface of the main reflector 12 toward the sub-reflector 13. Further, the cross-sectional shape of the first light-shielding member 19a is such that its inner diameter becomes thinner as it goes from the main reflector 12 side toward the sub-reflector 13 side. Further, in the cross-sectional shape of the first light-shielding member 19a, the angle θ1 (θ1m) formed by the inner diameter side surface (the optical axis side surface) and the surface orthogonal to the optical axis is smaller than the angle θ2 (θ2m) formed by the outer diameter side surface (the surface on the side opposite to the optical axis) and the surface orthogonal to the optical axis. Therefore, the thickness of the side surface of the first light-shielding member 19a is configured to become thicker from the main reflector 12 side toward the sub-reflector 13 side.

[0191] The second light-shielding member 19b separates the optical path of the light that passes through the correction plate 11 and is introduced into the main reflector 12 from the optical path of the light that is reflected by the main reflector 12, enters the sub-reflector 13, and is introduced into the opening 12b through the reflection by the sub-reflector 13. The second light-shielding member 19b is disposed on the side opposite to the optical axis of the light reflected by the sub-reflector 13 so as to surround the light beam reflected by the sub-reflector 13. As Figure 13 shown, the second light-shielding member 19b is a cylindrical member that is disposed so as to surround the reflecting surface 13a of the sub-reflector 13 disposed in the first region (disposed at the outer peripheral portion of the second reflecting portion). The second light-shielding member 19b is formed to project from the surface of the sub-reflector 13 toward the main reflector 12. Further, the cross-sectional shape of the second light-shielding member 19b is such that its inner diameter expands as it goes from the sub-reflector 13 side toward the main reflector 12 side. Further, in the cross-sectional shape of the second light-shielding member 19b, the angle θ1 (θ1s) formed by the inner diameter side surface (the optical axis side surface) and the surface orthogonal to the optical axis is smaller than the angle θ2 (θ2s) formed by the outer diameter side surface (the surface on the side opposite to the optical axis) and the surface orthogonal to the optical axis. Therefore, the thickness of the side surface of the second light-shielding member 19b is configured to become thinner from the sub-reflector 13 side toward the main reflector 12 side.

[0192] Such a first light-shielding member 19a and a second light-shielding member 19b preferably satisfy the following conditional expressions (11) to (13).

[0193] 1.0 < θ2s / θ1s < 2.0 (11)

[0194] 30° < θ2s < 90° (12)

[0195] 30° < θ2m < 90° (13)

[0196] Wherein,

[0197] θ1s: The angle formed by the inner-diameter side surface of the second light-shielding member 19b and a plane orthogonal to the optical axis

[0198] θ2s: The angle formed by the outer-diameter side surface of the second light-shielding member 19b and a plane orthogonal to the optical axis

[0199] θ2m: The angle formed by the outer-diameter side surface of the first light-shielding member 19a and a plane orthogonal to the optical axis

[0200] The conditional expressions (11) to (13) define the ratio of the angle formed by the outer-diameter side surface of the second light-shielding member 19b and a plane orthogonal to the optical axis to the angle formed by the inner-diameter side surface of the second light-shielding member 19b and a plane orthogonal to the optical axis when the angles θ2m and θ2s formed by the outer-diameter side surfaces of the first light-shielding member 19a and the second light-shielding member 19b and a plane orthogonal to the optical axis satisfy a predetermined condition. The first light-shielding member 19a and the second light-shielding member 19b satisfy the conditional expressions (11) to (13), thereby enabling effective removal of stray light.

[0201] In addition, in order to reliably obtain the effect of the conditional expression (11), preferably, the lower limit value of the conditional expression (11) is 1.095. In addition, in order to reliably obtain the effect of the conditional expression (11), preferably, the upper limit value of the conditional expression (11) is 1.595.

[0202] In addition, in order to reliably obtain the effect of the conditional expression (12), preferably, the lower limit value of the conditional expression (12) is 54.5°. In addition, in order to reliably obtain the effect of the conditional expression (12), preferably, the upper limit value of the conditional expression (12) is 84.5°.

[0203] In addition, in order to reliably obtain the effect of the conditional expression (13), preferably, the lower limit value of the conditional expression (13) is 55.0°. In addition, in order to reliably obtain the effect of the conditional expression (13), preferably, the upper limit value of the conditional expression (13) is 85.0°.

[0204] Specifically, Figure 13 The shapes of the first light-shielding member 19a and the second light-shielding member 19b shown have the relationship shown in Table 4 below. In addition, in Table 4, the taper is the value obtained by dividing the radius of the front-end side by the radius of the base-end side in the outer diameter and the inner diameter. Here, regarding the base-end side, if it is the first light-shielding member 19a, it is the end on the main mirror 12 side (image side), and if it is the second light-shielding member 19b, it is the end on the sub-mirror 13 side (object side). In addition, regarding the front-end side, if it is the first light-shielding member 19a, it is the end on the object side, and if it is the second light-shielding member 19b, it is the end on the image side.

[0205] (Table 4) Shapes of the First and Second Light-Shielding Members

[0206]

[0207]

[0208] As described above, the first light-shielding member 19a and the second light-shielding member 19b shown in Table 4 satisfy the above conditional expressions (7) to (9).

[0209] By forming the first light-shielding member 19a and the second light-shielding member 19b into the shapes as described above, in each of the optical systems UL of the present embodiment, while guiding the light contributing to imaging to the imaging element 14 (ensuring the light beam required for imaging), it is possible to effectively remove stray light such as light directly incident on the opening 12b through the correction plate 11 or light incident on the opening 12b by reflection from a portion other than the main reflecting mirror 12 and the sub-reflecting mirror 13. In addition, regarding the first light-shielding member 19a and the second light-shielding member 19b constituting the prevention portion 19, the above effects can be obtained not only by providing both but also by providing at least one of them.

[0210] (Position setting of the imaging element in the optical axis direction of each unit block)

[0211] In the above-described multi-eye structure camera module 1, for example, as shown in Figure 5 (b) etc., in each of the plurality of unit blocks 10, the optical system UL has the same structure, and in addition, all the imaging elements 14 are arranged at the same position with respect to the optical axis direction (for example, in such a manner that the focal plane in the infinitely far focused state substantially coincides with the imaging surface of the imaging element 14). Here, when the position of the imaging element 14 is changed in the optical axis direction with respect to the optical system UL, as also shown in the above description related to focusing, the focusing state (focusing distance) can be changed. Therefore, as shown in Figure 14 For each unit block 10 constituting one multi-eye structure camera module 1, the imaging elements 14 are arranged at different positions in the optical axis direction (in other words, at least two of the unit blocks 10 serving as the imaging units are arranged in such a manner that the relative positions of the optical system UL and the imaging element 14 in the optical axis direction are different), so that it is possible to simultaneously obtain images with different focusing distances for the same subject by one camera module 1.

[0212] Figure 14The three unit blocks 10a, 10b, and 10c that make up the camera module 1 are shown. Also, it is shown that the imaging element 14a of the unit block 10a is arranged such that its imaging surface is substantially coincident with the focal plane when the optical system UL is focused at infinity, the imaging element 14c of the unit block 10c is arranged such that its imaging surface is substantially coincident with the focal plane when the optical system UL is focused at the closest distance, and the imaging element 14b of the unit block 10b is arranged such that its imaging surface is substantially coincident with the focal plane when the optical system UL is focused at an intermediate focal length between infinity and the closest distance. The difference in the positions of the imaging elements in the optical axis direction only needs to be a value corresponding to the subject depth of the optical system UL.

[0213] In addition, when there are four or more unit blocks 10 that make up the multi-eye structure camera module 1, it can be configured such that the imaging element 14 of any one unit block 10 is arranged at the position in the infinity focus state, the imaging element 14 of any remaining one unit block 10 is arranged at the position in the closest focus state, and the imaging elements 14 of the remaining unit blocks 10 are arranged at positions that equally divide the focusing distance from infinity to the closest distance by the number of the remaining unit blocks 10. It can also be configured to be arranged before and after a predetermined focusing distance as the center. In addition, in one camera module 1, multiple unit blocks 10 with imaging elements 14 arranged at the same focusing distance can be provided. In addition, the position of the imaging element 14 in the optical axis direction with respect to the optical system UL (at least a part of the optical system UL or the position of the imaging element 14 in the optical axis direction) can also be changed.

[0214] In one multi-eye structure camera module 1, by providing unit blocks 10 with different positions of the imaging element 14 in the optical axis direction, it is possible to photograph images with different focusing distances for the same subject in one shot. In addition, by performing image processing on the images with different focusing distances, it is possible to generate an image with an arbitrary focusing distance. In addition, based on the difference in the focusing states of the multiple image signals obtained from the multiple imaging elements 14, it is also possible to calculate the distance to the subject.

[0215] In addition, by performing image processing on the images with different focusing distances, it is possible to generate a three-dimensional image of the subject, and in addition, it is possible to obtain the distance in the depth direction (height direction) of the subject. For example, by obtaining an image of a building in a state where the multi-eye structure camera module 1 of the present embodiment is mounted on a drone, it is possible to obtain the height of the building by performing image processing.

[0216] (Combination with lighting device)

[0217] Although the multi-eye structure camera module 1 of the present embodiment is composed of multiple unit blocks 10, all the unit blocks 10 are composed of the same optical system UL. Therefore, asFigure 15 As shown in FIG. 1 , in a part of the bit blocks 10 (for example, the unit blocks 10a and 10c), when a light source 70 composed of an LED or the like is arranged instead of the imaging element 14, the unit block 10 arranged with the light source 70 can be used as a lighting device. In the following description, the unit block 10b having the imaging element 14 is referred to as an "imaging block", and the unit blocks 10a and 10c having the light source 70 are referred to as "lighting blocks".

[0218] Here, in the unit block 10 (imaging block 10b) in which the imaging element 14 is arranged and the unit block 10 (illumination block 10a, 10c) in which the light source 70 is arranged, the positions of the imaging element 14 and the light source 70 in the optical axis direction of the optical system UL may be the same position or different positions. In addition, the unit block 10 (imaging block 10b) in which the imaging element 14 is arranged and the unit block 10 (illumination block 10a, 10c) in which the light source 70 is arranged are the same optical system UL, and in addition, by making the optical axis of the optical system UL arranged at the position corresponding to the light source 70 parallel to the optical axis of the optical system UL arranged at the position corresponding to the imaging element 14, the light source 70 is arranged at the same position as the imaging element 14 in the optical axis direction relative to the optical system UL, so that the field of view as the camera and the illumination field as the illumination device are roughly consistent. Therefore, when configured as described above, it is possible to be compact and effectively illuminate the light from the light source 70 to the photographic range (field of view) to obtain a bright image. In addition, as a countermeasure against ghosting of the light source 70 , the position of the light source 70 relative to the optical system UL and the position of the image sensor 14 relative to the optical system UL may be made different.

[0219] Figure 16 FIG. 1 shows an example of the arrangement of a camera unit block (imaging block) 10 and a lighting unit block (illumination block) 10 in a 3×3 camera module 1. For example, Figure 16 (a) is a case where the central unit block 10 is used as a camera and the peripheral unit blocks 10 are configured as lighting devices. Figure 16 In the structure of (a), the central camera is illuminated from the periphery, so bright illumination can be obtained, and the subject is illuminated from eight directions around the periphery, so the area where shadows are generated can be reduced (it can become a shadowless lamp). Figure 16 In the case of the camera module 1 having the structure of (a), a bright image without shadows can be obtained.

[0220] Figure 16(b) is a case where the middle layer in the horizontal (row direction) or vertical (column direction) is a unit block (shooting block) 10 of the camera, and the unit blocks (lighting blocks) 10 of the lighting device are arranged above and below or left and right thereof. Since the imaging element 14 is often rectangular (oblong), by arranging the unit blocks (shooting blocks) 10 of the camera in the short side direction of the imaging element 14, the difference in resolution based on the direction of the composite image can be reduced, and the illumination light is irradiated in a manner that sandwiches the camera, so that an image with less shadow can be obtained.

[0221] Figure 16 (c) is a case where four unit blocks 10 in the diagonal direction or the up, down, left, and right directions are the lighting device (lighting block), and the remaining unit blocks 10 are the camera (shooting block). In this Figure 16 structure of (c), the illumination light can be irradiated from four directions at 90 degrees different for photography, so that an image without shadow (can be a shadowless lamp) can be obtained. In addition, a stripe pattern (pattern imparting section) based on a liquid crystal display device or a transmissive screen is arranged on the object side of the correction plate 11 of the unit block (lighting block) 10 of the lighting device, and the four lighting devices (lighting blocks) are lit one by one to obtain an image, so that a super-resolution image based on structured illumination and the height measurement of the subject can be obtained.

[0222] In addition, as Figure 16 (d) shows, the central unit block 10 can also be configured as the lighting device (lighting block), and the remaining unit blocks 10 can be configured as the camera (shooting block).

[0223] In addition, it can also be a structure that changes the wavelength (changes the color) of the light emitted from the light source 70 of the unit block (lighting block) 10 of the lighting device, or a structure that arranges a polarizing plate on the object side of the correction plate 11 to change the polarization direction of the illumination light. In addition, as Figure 16 (a) shows, a switching unit 80 is provided, and the switching unit 80 switches either the imaging element 14 or the light source 70 and arranges it on the optical axis of the optical system UL, and it can also be arbitrarily selected Figure 16 the structures shown in (a) to (e). In addition, the imaging element 14 and the light source 70 can also be arranged in one component (for example, the above-mentioned imaging component 140).

[0224] (Multi-stage folding structure)

[0225] Regarding the optical system UL of the above embodiment, although it is a structure in which the main mirror 12 and the sub-mirror 13 are each folded back once (1-stage folding), by becoming a structure in which the main mirror 12 and the sub-mirror 13 are folded back two or more times (multi-stage folding), the overall length (the distance in the optical axis direction from the correction plate 11 to the imaging surface I) can be further shortened, and thus the camera modules 1 and 10 can be further miniaturized.

[0226] Figure 17 (a) shows a case where the reflecting surface of the first main reflector 121 that reflects the light transmitted through the correction plate 11 and the reflecting surface of the first sub-reflector 131 that reflects the light reflected by the first main reflector 121 form a reflecting surface pair, and the reflecting surface of the second main reflector 122 that reflects the light reflected by the first sub-reflector 131 and the reflecting surface of the second sub-reflector 132 that reflects the light reflected by the second main reflector 122 form a reflecting surface pair, respectively, and are configured as different components. In addition, Figure 17 (b) shows a case where the first main reflector 121 and the second main reflector 122 are configured as an integral component, and the first sub-reflector 131 and the second sub-reflector 132 are configured as an integral component. In Figure 17 In the case of (b), the reflecting surface of the first main reflector 121 and the reflecting surface of the second main reflector 122 are configured as a continuous surface, and the reflecting surface of the first sub-reflector 131 and the reflecting surface of the second sub-reflector 132 are configured as a continuous surface. In addition, either the reflecting surface of the first main reflector 121 and the reflecting surface of the second main reflector 122, or the reflecting surface of the first sub-reflector 131 and the reflecting surface of the second sub-reflector 132 may be configured as a continuous surface, and the other may be configured as a discontinuous surface.

[0227] In addition, the optical system UL of the present embodiment preferably satisfies the following conditional expression (14).

[0228] 2.0 < Fno < 15.0 (14)

[0229] Wherein,

[0230] Fno: F value of the optical system UL

[0231] The conditional expression (14) shows the appropriate range of the F value of the optical system UL. In addition, in order to reliably obtain the effect of the conditional expression (14), it is preferable that the upper limit value of the conditional expression (14) is 13.0, and more preferably 10.0. In addition, in order to reliably obtain the effect of the conditional expression (14), it is preferable that the lower limit value of the conditional expression (14) is 3.0, and further 4.0.

[0232] As described above, by making the number of reflections of the optical system UL multi-stage (increasing the number of reflecting surfaces), the degree of freedom in optical design can be improved. At this time, by using the above-described second structure (light-shielding member) for removing stray light, stray light can be removed even when performing multi-stage reflections.

[0233] In addition, the conditions and structures described above each exhibit the above-described effects, and are not limited to satisfying all the conditions and structures. Even if any one condition or structure is satisfied, or any combination of conditions or structures is satisfied, the above-described effects can be obtained.

[0234] Next, based on Figure 18 An optical device equipped with the camera module 1 of the present embodiment, that is, a camera, will be described. The camera 60 is configured to include the above-described camera module 1 having a multi-eye structure, a control unit 20, a storage unit 30, an input unit 40, and a display unit 50. In addition, the control unit 20 is an arithmetic processing device such as a CPU. In addition, the storage unit 30 is a storage device such as a RAM, a hard disk, or an SSD. In addition, if it is a camera, the input unit 40 is a shutter button or the like, and the display unit 50 is a liquid crystal display device or the like.

[0235] In this camera 60, light from an object (subject) (not shown) is condensed by each optical system UL of the plurality of unit blocks 10 constituting the camera module 1, and a subject image is formed on the imaging surface of the imaging element 14. Then, the subject image is photoelectrically converted by the photoelectric conversion element provided in the imaging element 14, and an image signal of the subject is output. This image signal is output to the control unit 20. The control unit 20 includes a generation unit that generates one image based on the plurality of image signals output from the plurality of imaging elements 14. In addition, through the control unit 20, the generated image is displayed on the display unit 50 provided in the camera 60. In addition, when the input unit 40 is operated by the photographer, after obtaining the image that has been photoelectrically converted by the imaging element 14 through the control unit 20, a synthesis process is performed, and the synthesized image is stored in the storage unit 30. Thus, the photographer can photograph the subject using this camera 60. In addition, the function of obtaining images from the plurality of imaging elements 14 and generating a synthesized image among the functions of the control unit 20 can be provided on the camera module 1 side, or can be provided on an external device for appropriate transmission and reception. In addition, the control unit 20 can also make the imaging conditions of each imaging element 14 different. As the imaging conditions, for example, at least one of the imaging sensitivity, exposure time, exposure start time, and exposure end time can be cited. By making the imaging conditions different, the synthesized image can be made closer to the image desired by the user.

[0236] This camera module 1 having a multi-eye structure preferably satisfies the following conditional expression (15).

[0237] 0.30 < Nc / (Nd × n) < 1.00 (15)

[0238] Among them,

[0239] Nd: The number of pixels of the imaging element 14

[0240] n: The number of imaging elements 14 used for generating the image

[0241] Nc: The number of pixels of the image

[0242] The conditional expression (15) shows the appropriate range of the ratio of the number of pixels of the image synthesized from the images obtained by these imaging elements 14 to the total number of pixels of the imaging elements 14 (the product of the number of pixels of the imaging element 14 each unit block 10 has and the number of unit blocks 10 used for generating the image). Additionally, in order to reliably obtain the effect of the conditional expression (15), it is preferable that the lower limit value of the conditional expression (15) be 0.40, and further 0.50. Additionally, in order to reliably obtain the effect of the conditional expression (15), it is preferable that the upper limit value of the conditional expression (15) be 0.80, 0.70, and further 0.60.

[0243] The camera module 1 with such a multi-eye structure preferably satisfies the following conditional expression (16).

[0244] 0.50 < Nc / (Nd × √n) < 2.00 (16)

[0245] Wherein,

[0246] Nd: The number of pixels of the imaging element 14

[0247] n: The number of imaging elements 14 used for generating the image

[0248] Nc: The number of pixels of the image

[0249] The conditional expression (16) shows the appropriate range of the ratio of the number of pixels of the image synthesized from the images obtained by these imaging elements 14 to the total number of pixels of the imaging elements 14 used for generating the composite image. Additionally, in order to reliably obtain the effect of the conditional expression (16), it is preferable that the lower limit value of the conditional expression (16) be 0.70, 0.80, and further 1.00. Additionally, in order to reliably obtain the effect of the conditional expression (16), it is preferable that the upper limit value of the conditional expression (16) be 1.90, 1.80, and further 1.70.

[0250] Additionally, regarding the optical device (camera 60) having a single-eye structure camera module 10, in Figure 18 where the unit block 10 corresponds to one structure, at this time, the control unit 20 does not perform the synthesis process.

[0251] Additionally, the above optical device is not limited to a camera, and also includes drones, portable terminals, endoscopes, etc. equipped with the camera modules 1 and 10 shown in this embodiment.

[0252] Hereinafter, referring to Figure 19A manufacturing method of the camera modules 1 and 10 of the present embodiment will be outlined. First, a first optical component 110 formed with a correction plate 11 and a sub-reflector 13, a second optical component 120 formed with a main reflector 12, a partition member 130, and an imaging component 140 configured with an imaging element 14 are prepared (step S100). Then, an optical system block portion 100 assembled with the first optical component 110, the second optical component 120, and the partition member 130 is configured (step S200), and the imaging component 140 is configured such that a plurality of optical systems UL of the optical system block portion 100 are aligned with the imaging element 14 (step S300). Thus, the camera modules 1 and 10 are manufactured.

[0253] With the structure described above, it is possible to provide the camera modules 1 and 10 having high resolution, high optical performance, and miniaturization, an optical device (camera 60) including the camera modules 1 and 10, and a manufacturing method of the camera modules 1 and 10.

[0254]

Embodiment

[0255] Hereinafter, each embodiment of the present application will be described with reference to the drawings. Figure 20 、 Figure 22 、 Figure 24 and Figure 26 are cross-sectional views showing the structures of the optical systems UL (UL1 to UL4) of the first to fourth embodiments.

[0256] In addition, in the first to tenth embodiments, when the height in the direction perpendicular to the optical axis is y, the distance along the optical axis (recess amount) from the tangent plane of each aspherical surface vertex at the height y to each aspherical surface is S(y), the radius of curvature of the reference spherical surface (paraxial radius of curvature) is r, the conic constant is K, and the n-th aspherical coefficient is An, the aspherical surface is represented by the following formula (b). In the following embodiments, "E-n" represents "×10 -n ".

[0257] S(y) = (y 2 / r) / {1 + (1 - K × y 2 / r 2 ) 1 / 2} + A2 × y 2 + A4 × y 4 + A6 × y 6 + A8 × y 8 (b)

[0258] In addition, in the tables of the respective embodiments, an asterisk mark is attached to the right of the surface number for the aspherical surface.

[0259] [First Embodiment]

[0260] Figure 20 This is a diagram showing the structure of the optical system UL1 of the first embodiment. When converted to a 35mm camera, the optical system UL1 has the structure of camera modules 1 and 10 with a focal length of 300mm.

[0261] The optical system UL1 is composed of a correction plate 11, a first reflecting surface 12a of a main mirror 12, a second reflecting surface 13a of a sub-mirror 13, and a refractive optical system 15 in the shape of a plano-convex lens with the convex surface facing the object side, in the order of the light traveling from the object side. In addition, a correction surface 11a is formed on the image side surface (the second surface) of the correction plate 11.

[0262] In Table 5 below, the values of the parameters of the optical system UL1 are shown. In this Table 5, f in all the parameters represents the focal length of the entire system, ω represents the semi-field angle, and TL represents the overall length. In addition, the overall length TL is the distance from the object side surface (the first surface) of the correction plate 11 to the image plane I in the direction of the optical axis incident on the image plane I. In addition, in the lens data, the first column m shows the order (surface number) of the lens surfaces from the object side along the direction of the light traveling, the second column r shows the radius of curvature of each lens surface, the third column d shows the distance on the optical axis from each optical surface to the next optical surface (surface interval), and the fourth column nd and the fifth column νd show the refractive index and Abbe number for the d line (λ = 587.6nm). In addition, a radius of curvature of ∞ represents a plane, and the refractive index of air 1.00000 is omitted.

[0263] Here, although the unit of the focal length f, the radius of curvature r, the surface interval d, and other lengths described in all the following parameter values is generally "mm", the same optical performance can be obtained even if the optical system is scaled up or down, so it is not limited to this. In addition, the explanations of these symbols and the explanations of the parameter table are the same in the subsequent embodiments.

[0264] (Table 5) First embodiment

[0265] [Overall parameters]

[0266] f = 20.58, ω = 3.61°, TL = 11.73, Fno = 2.00

[0267] [Lens data]

[0268]

[0269] In this optical system UL1, the second, third, fourth, and fifth surfaces are formed as aspherical shapes. In Table 6 below, the aspherical data, that is, the values of the conic constant K and the aspherical constants A2 to A8 are shown. In this Table 6, m represents the surface number (the same in the subsequent embodiments).

[0270] (Table 6)

[0271] [Aspherical data]

[0272]

[0273] The corresponding values of each conditional expression in the optical system UL1 are shown in Table 7 below.

[0274] (Table 7)

[0275] f1 = 22.75, RL = 8.81, D2 = 6.20, fa = 458.52, D0 = 11.52,

[0276] Y = 1.31, fb = 458.52, D1 = 10.60

[0277] (1) TL = 11.73

[0278] (2) ω = 3.61°

[0279] (3) f / fa = 0.04

[0280] (4) f / fb = 0.04

[0281] (5) M = 0.90

[0282] (6) f = 20.58

[0283] (7) RL / TL = 0.75

[0284] (8) D1 / RL = 1.20

[0285] (9) D1 / D2 = 1.71

[0286] (10) D0 / Y = 8.79

[0287] As described above, the optical system UL1 satisfies the above conditional expressions (1) to (10).

[0288] Figure 21The spherical aberration diagram, astigmatism diagram, distortion diagram, and coma diagram of the optical system UL1 are shown. In each aberration diagram, Y represents the image height and ω represents the semi-field angle. Additionally, the vertical axis of the spherical aberration diagram represents the aperture ratio relative to the maximum aperture, the vertical axes of the astigmatism diagram and the distortion diagram represent the image height, and the horizontal axis of the coma diagram represents the opening value in the exit pupil for each semi-field angle. D represents the d-line (λ = 587.6 nm), and g represents the g-line (λ = 435.8 nm). In the astigmatism diagram, the solid line represents the sagittal image plane and the dashed line represents the meridional image plane. Additionally, the same symbols as in this embodiment are also used in the aberration diagrams of the following embodiments. From these aberration diagrams, it can be seen that the optical system UL1 of the first embodiment corrects each aberration well and has excellent imaging performance.

[0289] [Second Embodiment]

[0290] Figure 22 FIG. is a diagram showing the structure of the optical system UL2 of the second embodiment. When converted to a 35 mm camera, the optical system UL2 has a structure of camera modules 1 and 10 with a focal length of 500 mm.

[0291] The optical system UL2 is composed, in the order of light travel from the object side, of a correction plate 11, a first reflecting surface 12a of a main mirror 12, a second reflecting surface 13a of a sub-mirror 13, and a refractive optical system 15 having a plano-concave lens shape with a concave surface facing the object side. Additionally, a correction surface 11a is formed on the image side surface (second surface) of the correction plate 11.

[0292] In Table 8 below, the parameter values of the optical system UL2 are shown.

[0293] (Table 8) Second Embodiment

[0294] [Overall Parameters]

[0295] f = 34.30, ω = 2.16°, TL = 12.00, Fno = 4.00

[0296] [Lens Data]

[0297]

[0298] In this optical system UL2, the second, third, and fourth surfaces are formed as aspherical surfaces. In Table 9 below, the aspherical data, i.e., the conic constant K and the values of each aspherical constant A2 to A8, are shown.

[0299] (Table 9)

[0300] [Aspherical Data]

[0301]

[0302] In Table 10 below, the corresponding values of each conditional expression in the optical system UL2 are shown.

[0303] (Table 10)

[0304] f1 = 35.02, RL = 9.09, D2 = 3.65, fa = 590.84, D0 = 9.60,

[0305] Y = 1.30, fb = 590.84, D1 = 8.99

[0306] (1) TL = 12.00

[0307] (2) ω = 2.16°

[0308] (3) f / fa = 0.06

[0309] (4) f / fb = 0.06

[0310] (5) M = 0.98

[0311] (6) f = 34.30

[0312] (7) RL / TL = 0.76

[0313] (8) D1 / RL = 0.99

[0314] (9) D1 / D2 = 2.46

[0315] (10) D0 / Y = 7.38

[0316] As described above, the optical system UL2 satisfies the above conditional expressions (1) to (10).

[0317] Figure 23 The spherical aberration diagram, astigmatism diagram, distortion diagram, and coma diagram of the optical system UL2 are shown. From these aberration diagrams, it can be seen that the optical system UL2 of the second embodiment corrects each aberration well and has excellent imaging performance.

[0318] [Third Embodiment]

[0319] Figure 24 It is a diagram showing the structure of the optical system UL3 of the third embodiment. When converted to a 35 mm camera, the optical system UL3 has a structure of camera modules 1 and 10 with a focal length of 1000 mm.

[0320] The optical system UL3 is composed of a correction plate 11, a first reflecting surface 12a of the main mirror 12, a second reflecting surface 13a of the sub-mirror 13, and a refractive optical system 15 having a plano-concave lens shape with a concave surface facing the object side, in the order of light traveling from the object side. In addition, a correction surface 11a is formed on the image side surface (the second surface) of the correction plate 11.

[0321] In Table 11 below, the values of the parameters of the optical system UL3 are shown.

[0322] (Table 11) Third Embodiment

[0323] [Overall Parameters]

[0324] f = 68.60, ω = 1.09°, TL = 15.00, Fno = 8.00

[0325] [Lens Data]

[0326]

[0327] In this optical system UL3, the second, third, and fourth surfaces are formed into aspherical shapes. In Table 12 below, the aspherical data, that is, the values of the conic constant K and the aspherical constants A2 to A8 are shown.

[0328] (Table 12)

[0329] [Aspherical Data]

[0330]

[0331] In Table 13 below, the corresponding values of each conditional expression in the optical system UL3 are shown.

[0332] (Table 13)

[0333] f1 = 77.73, RL = 12.09, D2 = 2.6, fa = 1120.45, D0 = 10.39,

[0334] Y = 1.30, fb = 1120.45, D1 = 10.6

[0335] (1) TL = 15.00

[0336] (2) ω = 1.09°

[0337] (3) f / fa = 0.06

[0338] (4) f / fb = 0.06

[0339] (5) M = 0.88

[0340] (6) f = 68.60

[0341] (7) RL / TL = 0.81

[0342] (8) D1 / RL = 0.88

[0343] (9) D1 / D2 = 4.08

[0344] (10) D0 / Y = 7.99

[0345] As described above, the optical system UL3 satisfies the above conditional expressions (1) to (10).

[0346] Figure 25 The spherical aberration diagram, astigmatism diagram, distortion diagram, and coma diagram of the optical system UL3 are shown. From these aberration diagrams, it can be seen that the optical system UL3 of the third embodiment corrects each aberration well and has excellent imaging performance.

[0347] [Fourth Embodiment]

[0348] Figure 26 FIG. is a diagram showing the structure of the optical system UL4 of the fourth embodiment. When converted to a 35 mm camera, the optical system UL4 has a structure of camera modules 1 and 10 with a focal length of 300 mm.

[0349] The optical system UL4 is composed of a correction plate 11, a first reflecting surface 12a of the main mirror 12, and a second reflecting surface 13a of the sub-mirror 13 in the order of light travel from the object side. In addition, a correction surface 11a is formed on the object-side surface (the first surface) of the correction plate 11.

[0350] In Table 14 below, the parameter values of the optical system UL4 are shown.

[0351] (Table 14) Fourth Embodiment

[0352] [Overall Parameters]

[0353] f = 19.71, ω = 0.87°, TL = 6.00, Fno = 5.00

[0354] [Lens Data]

[0355]

[0356] In this optical system UL4, the first surface is formed in an aspherical shape. In Table 15 below, the aspherical data, that is, the values of the conic constant K and the aspherical constants A2 to A8 are shown.

[0357] (Table 15)

[0358] [Aspherical Data]

[0359]

[0360] In Table 16 below, the corresponding values of each conditional expression in the optical system UL4 are shown.

[0361] (Table 16)

[0362] f1 = 22.89, RL = 3.46, D2 = 0.90, fa = 545.33, D0 = 4.11,

[0363] Y = 0.31, fb = 545.33, D1 = 4.00

[0364] (1) TL = 6.00

[0365] (2) ω = 0.87°

[0366] (3) f / fa = 0.04

[0367] (4) f / fb = 0.04

[0368] (5) M = 0.86

[0369] (6) f = 19.71

[0370] (7) RL / TL = 0.58

[0371] (8) D1 / RL = 1.16

[0372] (9) D1 / D2 = 4.44

[0373] (10) D0 / Y = 13.26

[0374] As described above, the optical system UL4 satisfies the above conditional expressions (1) to (10).

[0375] Figure 27 The spherical aberration diagram, astigmatism diagram, distortion diagram, and coma diagram of the optical system UL4 are shown. From these aberration diagrams, it can be seen that the optical system UL4 of the fourth embodiment corrects each aberration well and has excellent imaging performance.

[0376] The following fifth to seventh embodiments are cases where the optical system UL is configured by a compact Schmidt-Cassegrain method. In addition, Figure 28 is a cross-sectional view of the optical system UL that constitutes the camera modules 1 and 10 of the fifth to seventh embodiments.

[0377] (Fifth Embodiment)

[0378] The fifth embodiment is a case where the optical system UL is configured by a compact Schmidt-Cassegrain method, and is the structure of the camera modules 1 and 10 whose focal length becomes 500 mm when converted to a 35 mm camera. In addition, the imaging element 14 is a two-million-pixel and 1 / 6-inch imaging element, and its size is 2.4 mm × 1.8 mm.

[0379] In Table 17 below, the parameters of the optical system UL in the fifth embodiment are shown. Here, f1 represents the focal length of the primary mirror 12, r1 represents the radius of curvature of the primary mirror 12, f2 represents the focal length of the secondary mirror 13, r2 represents the radius of curvature of the secondary mirror 13, f represents the focal length of the entire system, R represents the distance on the optical axis from the secondary mirror 13 to the primary mirror 12, D represents the distance on the optical axis from the object-side surface of the correction plate 11 to the primary mirror 12, TL represents the overall length, i.e., the distance on the optical axis from the object-side surface of the correction plate 11 to the image plane I, FNo represents the F-number, and M represents the secondary magnification ratio.

[0380] (Table 17) Fifth Embodiment - Optical System UL

[0381] f1 = 6.12, r1 = 12.24, f2 = 0.75, r2 = 1.50, f = 34.3,

[0382] R = 5.5, D = 6.0, TL = 9.4, FNO = 5.7, M = 5.60

[0383] In addition, in Table 18 below, the parameters of the camera module 1 having a multi-eye structure composed of nine 3×3 elements that make up the above optical system UL are shown. Additionally, the combined F-number is the F-number of the image obtained by combining the images based on each of the nine optical systems UL. Since it is composed of a 3×3 optical system UL, the overall F-number (combined F-number) becomes 1 / 3 of the F-number of each optical system UL. Additionally, the size represents the length in the horizontal × vertical × depth direction (optical axis direction) when the camera module 1 is viewed from the object side. Additionally, the zoom represents the focal length when converted to a 35mm camera in the telephoto end state and the wide-angle end state.

[0384] (Table 18) Fifth Embodiment - Camera Module 1

[0385]

[0386] As described above, by making the optical systems UL of the camera modules 1 and 10 a compact Schmidt-Cassegrain type, it becomes a telephoto optical system with a focal length of 500 mm in terms of a 35mm camera, and at the same time, the overall length can be made much shorter than the focal length. Additionally, since it is a compact Schmidt-Cassegrain type, it can become an aplanatic optical system (an optical system without spherical aberration, coma, and astigmatism). And it is possible to realize a multi-eye structure camera module 1 with a thickness (length in the optical axis direction) of less than 10 mm.

[0387] (Sixth Embodiment)

[0388] The sixth embodiment is a case where the optical system UL is configured in a compact Schmidt-Cassegrain format, and it is the structure of the camera modules 1 and 10 with a focal length of 300 mm when converted to a 35 mm camera. Additionally, the imaging element 14 is the same as in the fifth embodiment, a two-million-pixel and 1 / 6-inch imaging element with a size of 2.4 mm × 1.8 mm.

[0389] In Table 19 below, the parameters of the optical system UL in the sixth embodiment are shown.

[0390] (Table 19) Sixth Embodiment - Optical System UL

[0391] f1 = 3.67, r1 = 7.34, f2 = 0.45, r2 = 0.90, f = 20.6,

[0392] R = 3.3, D = 3.6, TL = 5.64, FNO = 3.4, M = 5.61

[0393] Additionally, in Table 20 below, the parameters of the camera module 1 with a multi-eye structure constituting the above optical system UL by nine 3×3 are shown.

[0394] (Table 20) Sixth Embodiment - Camera Module 1

[0395]

[0396] As described above, by making the optical system UL of the camera modules 1 and 10 in a compact Schmidt-Cassegrain format, it becomes a telephoto optical system with a focal length of 300 mm when converted to a 35 mm camera, and at the same time, the overall length can be made much shorter than the focal length. Additionally, since it is a compact Schmidt-Cassegrain format, it can be an anastigmatic optical system (an optical system without spherical aberration, coma, and astigmatism). And a camera module 1 with a thickness (length in the optical axis direction) of less than 10 mm can be achieved.

[0397] (Seventh Embodiment)

[0398] The seventh embodiment is a case where the optical system UL is configured in a compact Schmidt-Cassegrain format, and it is the structure of the camera modules 1 and 10 with a focal length of 1000 mm when converted to a 35 mm camera. Additionally, the imaging element 14 is the same as in the fifth embodiment, a two-million-pixel and 1 / 6-inch imaging element with a size of 2.4 mm × 1.8 mm

[0399] In Table 21 below, the parameters of the optical system UL in the seventh embodiment are shown.

[0400] (Table 21) Seventh Embodiment - Optical System UL

[0401] f1 = 12.24, r1 = 24.5, f2 = 1.50, r2 = 3.00, f = 68.6,

[0402] R = 11.0, D = 12.0, TL = 18.8, FNO = 11.4, M = 5.60

[0403] In addition, in Table 22 below, the parameters of the camera module 1 having a multi-eye structure of the above-described optical system UL composed of 9 elements of 3×3 are shown.

[0404] (Table 22) Seventh Embodiment - Camera Module 1

[0405]

[0406] As described above, by making the optical system UL of the camera module 1 a compact Schmidt-Cassegrain type, it becomes a telephoto optical system with a focal length of 1000 mm in terms of 35 mm camera conversion, and at the same time, the overall length can be made much shorter than the focal length. In addition, since it is a compact Schmidt-Cassegrain type, it can be an anastigmatic optical system (an optical system without spherical aberration, coma, and astigmatism). And a camera module 1 with a thickness (length in the optical axis direction) smaller than 20 mm can be realized.

[0407] (Reference Example)

[0408] As a reference example, in Table 23 below, the parameters of the optical system UL in which the optical system UL is configured by the Schmidt-Cassegrain method and the focal length becomes 300 mm when converted to a 35 mm camera are shown. In addition, in this reference example, the imaging element 14 is also the same as that in the fifth embodiment, a two-million-pixel and 1 / 6-inch imaging element, and its size is 2.4 mm × 1.8 mm.

[0409] (Table 23) Reference Example

[0410] f1 = 14.3, r1 = 28.6, f2 = 14.3, r2 = 28.6, f = 24.0,

[0411] R = 10.0, D = 14.3, TL = 15.9

[0412] When the optical system UL is configured by the Schmidt-Cassegrain method, when converted to a 35 mm camera, it becomes a telephoto optical system with a focal length of 300 mm, and at the same time, the overall length can be made shorter than the focal length, and an optical system without field curvature, that is, with a Petzval sum of zero, can be configured. However, compared with the compact Schmidt-Cassegrain type, the overall length becomes longer.

[0413] As described above, in the camera modules 1 and 10 according to the present embodiment, by arranging the optical system UL of the compact Schmidt-Cassegrain type in a plurality of arrays, it is possible to provide a telephoto camera module with high resolution and thinness (small size in the optical axis direction).

[0414] Regarding the camera modules 1 and 10 of the present embodiment, as described above, on each of the two planar optical components (parallel planar glass plates 111 and 121), a plurality of correction plates 11, a plurality of main reflectors 12, and a plurality of sub-reflectors 13 can be formed by imprinting or mask coating, and the first optical component 110, the second optical component 120, and the partition member 130 are combined one by one to complete. Therefore, the camera modules 1 and 10 of the present embodiment do not need to adjust the positions of each other after separately forming a plurality of optical systems to form an optical system block, but can be manufactured by a simple process. In addition, a plurality of imaging elements 14 form an imaging component 140, which can be combined with the optical system block 100. Without adjusting the positions of the optical system and the imaging elements for each individual, it can be manufactured by an even simpler process. In addition, since it is difficult to generate errors in the positions of the plurality of imaging elements 14 relative to each other after manufacturing, it is possible to form a camera module 1 that synthesizes a plurality of images and can perform high-resolution photography.

[0415] Here, the number of correction plates 11 included in the first optical component 110 is equal to the number of sub-reflectors 13. In addition, the number of sub-reflectors 13 included in the first optical component 110 is equal to the number of main reflectors 12 included in the second optical component 120. In addition, the number of optical systems UL included in the optical system block 100 is equal to the number of optical systems UL that can be isolated by the partition member 130.

[0416] In addition, although the correction plate 11 is provided in the present embodiment, it is not limited thereto, and the upper surface of the parallel planar glass plate 111 may be left as it is without providing the correction plate 11. In addition, in the present embodiment, the correction plate 11 and the sub-reflector 13 are not integrated but separated, and the position of the correction plate 11 is not limited thereto. In addition, the shape of the correction plate 11 is not particularly limited and can be appropriately changed.

[0417] In addition, although the sub-reflector 13 and the main reflector 12 are respectively provided on the parallel planar glass plates 111 and 121 in the present embodiment, the shape and material of the glass plates are not limited, and they may not be parallel or planar, and may also be plate members made of resin materials.

[0418] In addition, the forming methods of the main mirror 12, the sub-mirror 13, etc. can be appropriately changed. Although they are combined after the first optical component 110 and the second optical component 120 are formed, the first optical component 110, the second optical component 120, and the partition member 130 can also be sequentially formed on the surface of the reference board member.

[0419] The plan view shape of the area partitioned by the partition member 130 (the shape when observing the optical system UL along the optical axis direction of the light incident on the imaging element 14) is preferably the same as the plan view shape of the imaging element 14. For example, when the plan view shape of the imaging element 14 is rectangular, it is preferable that the plan view shape of the area partitioned by the partition member 130 is also rectangular. In addition, the plan view shapes of the main mirror 12 and the sub-mirror 13 can also be appropriately changed, and preferably, they are the same as the plan view shape of the imaging element 14. The plan view shapes of the opening 12b, the correction plate 11, and the refractive optical system 15 can also be appropriately changed, and preferably, they are the same as the plan view shape of the imaging element 14.

[0420] In the present embodiment, although the partition member 130 is provided as a light-blocking member, it can be appropriately changed as long as the light incident on the optical system UL can be suppressed from entering the adjacent optical system UL. For example, it can also be a diffusing member such as frosted glass. In addition, the light-blocking member does not need to completely suppress the incidence of light, as long as it can suppress the incidence of light to such an extent that it does not affect the imaging element 14 (for example, 20% of the incident light).

[0421] In addition, in the multi-eye camera module 1 of the present embodiment, although all nine optical systems UL are described as being the same, optical systems with different optical characteristics such as multiple focal lengths, shooting distances, or F-numbers can also be combined as one optical device. At this time, when at least one compact Schmidt-Cassegrain type optical system as in the present embodiment is provided, long focal distance photography can be performed, which is preferable.

[0422] In addition, when combining multiple optical systems UL with different optical characteristics, the shapes of a part of the nine main mirrors (or sub-mirrors) can be changed, the focal lengths of a part of the nine correction plates can be changed, or refractive optical systems with different focal lengths can be arranged in the nine optical systems UL respectively.

[0423] In addition, in the multi-eye camera module 1, at least one of the nine optical systems UL can also be made into an illumination optical system. At this time, only the imaging element 14 of the optical system UL of the present embodiment can be replaced with an illumination unit such as an LED, or the mirrors and correction plates can be omitted in the area where the light from the illumination unit is incident.

[0424] In addition, in the camera module 1 with a multi-eye structure, although the nine optical systems UL move as a unit when performing focusing or the like, they can also be moved in such a way as to change the distance between at least a part of the optical systems UL and the imaging element 14.

[0425] (The structure where the optical systems UL are integrated)

[0426] In the above structure, as Figure 6 shown, although the case where the first optical component 110 and the second optical component 120 are formed as separate entities has been described, it can also be as Figure 29 shown. A medium that transmits light (a transmissive component having a refractive index) is filled between the first optical component 110 and the second optical component 120 to form an optical component 171, and a correction surface 11a, a first reflection surface 12a, and a second reflection surface 13a are provided on the optical component 171 to form an integrated lens 170 that makes the optical systems UL integrated. In addition, in the integrated lens 170, a stray light removal component (the partition component 130) can be omitted.

[0427] Specifically, as Figure 29 shown, the optical component 171 includes: a first surface 171a, which is an incident surface for light from an object and has a correction surface 11a formed thereon; a second surface 171b, on which a first reflection surface 12a that reflects light incident through the first surface 171a is formed; a third surface 171c, on which a second reflection surface 13a that reflects light incident after being reflected by the first reflection surface 12a is formed; and a fourth surface 171d as an emission surface, from which the light reflected by the second reflection surface 13a is emitted from the optical component 171 toward the imaging element 14.

[0428] In the optical component 171, although the first surface 171a can be a flat surface or a surface with curvature, it is preferably in a shape with a concave surface facing the object side. In addition, although the fourth surface 171d can be a flat surface or a surface with curvature, it is preferably in a shape with a convex surface facing the object side. Regarding the fourth surface 171d, in the case of a surface with curvature, it functions as the above-mentioned refractive optical system 15.

[0429] In addition, it is preferable that the inner diameter side of the straight line (hereinafter referred to as "the first straight line 171e") connecting the edge portion inside the inner diameter of the second surface 171b on which the first reflection surface 12a is formed and the edge portion outside the outer diameter of the fourth surface 171d is an air portion (concave shape, recess) 171f.

[0430] Although they are arranged on the optical path in the order of the first surface 171a, the second surface 171b, the third surface 171c, the fourth surface 171d, and the imaging surface I of the imaging element 14, when the integral lens 170 is observed from the lateral direction (the direction orthogonal to the optical axis), they are arranged in the order of the third surface 171c, the first surface 171a, the fourth surface 171d, the second surface 171b, and the imaging surface I. The first surface 171a and the fourth surface 171d are preferably arranged between the second surface 171b and the third surface 171c. Therefore, when the integral lens 170 is observed from the lateral direction, the center is a surface recessed toward the object side, and a convex portion (the protruding portion between the third surface 171c and the first surface 171a where the second reflecting surface 13a is formed on the image side) 171g is arranged at the position closest to the object side.

[0431] Preferably, at least a part of the outer edge of the air portion 171f, the outer edge of the convex portion 171g, and the outer edge of the integral lens 170 connecting the first surface 171a and the second surface 171b, for example, is blackened or the like to have a function of removing stray light. The outer edge of the integral lens 170 may also have a function of removing stray light on the side closest to the object side, while not having a function of removing stray light on the side closest to the image side (in other words, only a part may be a blackened portion).

[0432] In addition, in order to perform molding processing and hold the lens, the outer edges of the integral lens 170 and the convex portion 171g are preferably stepped. Moreover, preferably, in order to remove stray light, at least a part of the outer edges of the integral lens 170 and the convex portion 171g has an inclined surface that is inclined in a direction separating from the optical axis as it gets closer to the imaging surface.

[0433] Regarding this optical component 171, it is preferable to fill a resin material between the first surface 171a and the second surface 171b. In addition, regarding the resin material of the optical component 171, it is preferable to use a material with zero or substantially zero birefringence (for example, a material with zero or substantially zero in-plane retardation Re, thickness retardation Rth, and photoelastic coefficient C).

[0434] The optical system UL of the integral lens 170 as described above preferably satisfies the following conditional expression (17).

[0435] 0.5 < (h1in / d1 - i) / (h4 / d4 - i) < 10.0 (17)

[0436] Among them,

[0437] h1in: The inner diameter of the refracting surface (the first surface 171a) at the position closest to the object side

[0438] d1 - i: The distance between the optical axis center of the refracting surface (the first surface 171a) at the position closest to the object side and the image surface

[0439] h4: Outer diameter of the refracting surface (the 4th surface 171d) located at the position closest to the image plane side

[0440] d4-i: Spacing between the optical axis center of the refracting surface (the 4th surface 171d) located at the position closest to the image plane side and the image plane

[0441] The conditional expression (17) stipulates an appropriate relationship between the 1st surface 171a, which is the refracting surface located at the position closest to the object side and serves as the incident surface, and the 4th surface 171d, which is the refracting surface located at the position closest to the image plane side and serves as the exit surface, in the integral type lens 170. When it is lower than the lower limit value of the conditional expression (17), stray light that does not pass through the reflecting surface reaches the image plane, so it is not preferable. Additionally, in order to reliably obtain the effect of the conditional expression (17), more preferably, the lower limit value of the conditional expression (17) is 0.6, and further 0.7. Also, when it exceeds the upper limit value of the conditional expression (17), vignetting of the peripheral portion of the signal light becomes larger and the resolution decreases, so it is not preferable. Additionally, in order to reliably obtain the effect of the conditional expression (17), more preferably, the upper limit value of the conditional expression (17) is 7.0, and further 5.0.

[0442] In addition, the integral type lens 170 as described above preferably satisfies the following conditional expression (18).

[0443] 50.0 < νd (18)

[0444] Wherein,

[0445] νd: Abbe number for the d-line of the medium (the medium of the optical component 171) of the integral type lens 170

[0446] The conditional expression (18) stipulates an appropriate value for the Abbe number for the d-line of the medium of the optical component 171 that constitutes the integral type lens 170. When it is lower than the lower limit value of the conditional expression (18), the chromatic aberration of the integral type lens 170 deteriorates, so it is not preferable. Additionally, in order to reliably obtain the effect of the conditional expression (18), more preferably, the lower limit value of the conditional expression (18) is 54.0, and further 60.0.

[0447] In addition, the optical system UL of the integral type lens 170 as described above preferably satisfies the following conditional expression (19).

[0448] 0.1 < r4 / TL3 < 10.0 (19)

[0449] Wherein,

[0450] r4: Curvature radius of the refracting surface (the 4th surface 171d) located at the position closest to the image plane side

[0451] TL3: The distance between the reflecting surface (the third surface 171c) located at the position closest to the object and the image plane

[0452] The conditional expression (19) defines the ratio of the radius of curvature of the refracting surface (the fourth surface 171d) located at the position closest to the image plane to the overall length of the one-piece lens 170 (the distance between the reflecting surface (the third surface 171c) located at the position closest to the object and the image plane). When it is below the lower limit value of the conditional expression (19), chromatic aberration and Petzval sum deteriorate, so it is not preferable. Further, in order to reliably obtain the effect of the conditional expression (19), more preferably, the lower limit value of the conditional expression (19) is 0.15, and further 0.2. Also, when it exceeds the upper limit value of the conditional expression (19), it is difficult to correct off-axis aberrations, so it is not preferable. Further, in order to reliably obtain the effect of the conditional expression (19), more preferably, the upper limit value of the conditional expression (19) is 7.0, and further 5.0.

[0453] [Embodiment]

[0454] The following-described Eighth Embodiment to Tenth Embodiment are embodiments of the one-piece lens 170. Further, Figure 30 , Figure 32 and Figure 34 show the optical systems UL (UL8 to UL10) of the one-piece lens 170 in the Eighth to Tenth Embodiments. For Figure 29 the optical components 171, 1 represents the first surface 171a, 2 represents the first reflecting surface 12a (the second surface 171b), 3 represents the second reflecting surface 13a (the third surface 171c), and 4 represents the fourth surface 171d.

[0455] In each embodiment, the aspherical surface is represented by the above-described formula (b). Further, in each embodiment, the aspherical coefficient A2 is 0. Further, in the tables of each embodiment, an asterisk mark is attached to the right of the surface number for the aspherical surface.

[0456] (Eighth Embodiment)

[0457] Figure 30 shows the optical system UL8 of the one-piece lens 170 in the Eighth Embodiment. The values of the parameters of this optical system UL8 are shown in Table 24 below. In Table 24, in all the parameters, f represents the focal length of the entire system, ω represents the semi-field angle, FNO represents the F-number, Y represents the maximum image height, Bf represents the back focal length, and TL3 represents the overall length. Here, as described above, the overall length TL3 represents the distance on the optical axis from the third surface to the image plane I. Further, the back focal length Bf represents the distance on the optical axis from the optical surface closest to the image side ( Figure 29 the second surface in) to the image plane I.

[0458] (Table 24) Eighth Embodiment

[0459] [All parameters]

[0460] f = 21.970, ω(°) = 4.087, FNO = 2.0, Y = 1.6,

[0461] BF = 2.4000, TL3 = 9.0000

[0462] [Lens data]

[0463]

[0464] In the optical system UL8, the optical surfaces of the first, second, third, and fourth surfaces are formed into aspherical shapes. In Table 25 below, the aspherical data, that is, the values of the conic constant K and the aspherical constants A4 to A6, are shown for each surface m.

[0465] (Table 25)

[0466] [Aspherical data]

[0467]

[0468] In Table 26 below, the corresponding values of the conditional expressions in the optical system UL8 are shown.

[0469] (Table 26)

[0470] h1in = 3.19, d1-i = 7.80, h4 = 1.75, d4-i = 5.80,

[0471] (17) (h1in / d1-i) / (h4 / d4-i) = 1.355

[0472] (18) νd = 57.07

[0473] (19) r4 / TL3 = 2.111

[0474] As described above, the optical system UL8 satisfies all of the above conditional expressions (17) to (19).

[0475] Figure 31 The spherical aberration diagram, astigmatism diagram, distortion diagram, and coma diagram of the optical system UL8 of the integral lens 170 of the eighth embodiment are shown. From these aberration diagrams, it can be seen that the optical system UL8 corrects each aberration well and has excellent imaging performance.

[0476] (The ninth embodiment)

[0477] Figure 32The optical system UL9 of the integrated lens 170 in the 9th embodiment is shown. The values of the parameters of the optical system UL9 are shown in Table 27 below.

[0478] (Table 27) 9th embodiment

[0479] [Overall parameters]

[0480] f = 40.000, ω(°) = 2.259, FNO = 3.5, Y = 1.6,

[0481] BF = 3.0500, TL3 = 11.0000

[0482] [Lens data]

[0483]

[0484] In this optical system UL9, the optical surfaces of the 1st, 2nd, 3rd, and 4th surfaces are each formed into an aspherical shape. In Table 28 below, the aspherical data, that is, the conic constant K and the values of the respective aspherical constants A4 to A6, are shown for each surface m.

[0485] (Table 28)

[0486] [Aspherical data]

[0487]

[0488]

[0489] In Table 29 below, the corresponding values of the respective conditional expressions in the optical system UL9 are shown.

[0490] (Table 29)

[0491] h1in = 3.50, d1-i = 8.00, h4 = 1.75, d4-i = 8.05

[0492] (17) (h1in / d1-i) / (h4 / d4-i) = 2.013

[0493] (18) νd = 57.75

[0494] (19) r4 / TL3 = 0.590

[0495] As described above, the optical system UL9 satisfies all of the above conditional expressions (17) to (19).

[0496] Figure 33The spherical aberration diagram, astigmatism diagram, distortion diagram, and coma diagram of the optical system UL9 of the integrated lens 170 according to the 9th embodiment are shown. From these aberration diagrams, it can be seen that the optical system UL9 corrects each aberration well and has excellent imaging performance.

[0497] (10th embodiment)

[0498] Figure 34 The optical system UL10 of the integrated lens 170 according to the 10th embodiment is shown. The values of the parameters of this optical system UL10 are shown in Table 30 below.

[0499] (Table 30) 10th embodiment

[0500] [Overall parameters]

[0501] f = 60.000, ω(°) = 1.489, FNO = 6.0, Y = 1.6,

[0502] BF = 5.0000, TL3 = 13.0000

[0503] [Lens data]

[0504]

[0505]

[0506] In this optical system UL10, the optical surfaces of the 1st, 2nd, 3rd, and 4th surfaces are formed into aspherical shapes. In Table 31 below, for each surface m, the aspherical data, that is, the conic constant K and the values of each aspherical constant A4 to A6 are shown.

[0507] (Table 31)

[0508] [Aspherical data]

[0509]

[0510] In Table 32 below, the corresponding values of each conditional expression in the optical system UL10 are shown.

[0511] (Table 32)

[0512] h1in = 2.00, d1-i = 1.30, h4 = 1.10, d4-i = 6.00

[0513] (17) (h1in / d1-i) / (h4 / d4-i) = 0.839

[0514] (18) νd = 64.13

[0515] (19) r4 / TL3 = 0.302

[0516] As described above, the optical system UL10 satisfies all of the above conditional expressions (17) to (19).

[0517] Figure 35 The spherical aberration diagram, astigmatism diagram, distortion diagram, and coma diagram of the optical system UL10 of the integrated lens 170 according to the tenth embodiment are shown. From these aberration diagrams, it can be seen that the optical system UL10 corrects each aberration well and has excellent imaging performance.

[0518] Reference numeral description

[0519] 10 Camera module UL optical system

[0520] 11 Correction plate (correction component) 11a Correction surface

[0521] 12 Main reflector (first reflection part) 12a First reflection surface

[0522] 13 Sub-reflector (second reflection part) 13a Second reflection surface

[0523] 14 Imaging element 60 Camera (optical device)

[0524] 100 Optical system block part 110 First optical component 120 Second optical component

[0525] 130 Partition member 140 Imaging part

Claims

1. An optical system includes an incident surface, a first reflecting portion, and a second reflecting portion, and forms an image of an object. The incident surface receives light from the object side. The first reflecting portion reflects the light that has passed through the incident surface. The second reflecting portion reflects the light reflected by the first reflecting portion, where in the optical path, the medium between the first reflecting portion and the second reflecting portion is an integral transmissive member having a refractive index. The incident surface is formed on the first surface of the transmissive member on the object side where light is incident. The reflecting surface serving as the first reflecting portion is formed on the second surface of the transmissive member on the image side where the light that has passed through the incident surface is incident. The reflecting surface serving as the second reflecting portion is formed on the third surface of the transmissive member on the object side where the light reflected by the first reflecting portion is incident. A fourth surface serving as an exit surface is formed. The exit surface is a surface on the image side of the transmissive member and receives the light reflected by the second reflecting portion, and allows the light to exit the transmissive member. When observing the optical system from the lateral direction, i.e., the direction orthogonal to the optical axis, the third surface, the first surface, the fourth surface, and the second surface are arranged in this order from the object side toward the image side, and the portion of the third surface closest to the image side is arranged at a position closer to the object side than the portion of the first surface closest to the object side, and the portion of the fourth surface closest to the image side is arranged at a position closer to the object side than the portion of the second surface closest to the object side. The optical system satisfies the conditions of the following formula: TL < 15.0 mm 2.0 < Fno < 15.0 -0.1 < f / fx < 0.1 3.0<M<8.0 where TL: The distance from the surface closest to the object side of the optical system to the image surface in the direction of the optical axis where light is incident on the image surface. Fno: The F-number of the optical system. f: The focal length of the entire optical system. fx: The focal length of the incident surface or the optical component on which the incident surface is formed. M = f / f1 f1: The focal length of the first reflecting portion.

2. An optical system includes an incident surface, a first reflecting portion, and a second reflecting portion, and forms an image of an object. The incident surface receives light from the object side. The first reflecting portion reflects the light that has passed through the incident surface. The second reflecting portion reflects the light reflected by the first reflecting portion, where in the optical path, the medium between the first reflecting portion and the second reflecting portion is an integral transmissive member having a refractive index. The incident surface is formed on the first surface of the transmissive member on the object side where light is incident. The reflecting surface serving as the first reflecting portion is formed on the second surface of the transmissive member on the image side where the light that has passed through the incident surface is incident. The reflecting surface serving as the second reflecting portion is formed on the third surface of the transmissive member on the object side where the light reflected by the first reflecting portion is incident. A fourth surface serving as an exit surface is formed. The exit surface is a surface on the image side of the transmissive member and receives the light reflected by the second reflecting portion, and allows the light to exit the transmissive member. When observing the optical system from the lateral direction, i.e., the direction orthogonal to the optical axis, the surfaces are arranged in the order of the third surface, the first surface, the fourth surface, and the second surface from the object side toward the image side, and the portion of the third surface closest to the image side is arranged closer to the object side than the portion of the first surface closest to the object side, and the portion of the fourth surface closest to the image side is arranged closer to the object side than the portion of the second surface closest to the object side. When observing from the direction orthogonal to the optical axis of the optical system, the reflecting surface of the second reflecting portion is arranged closer to the object side than the incident surface. The optical system satisfies the condition of the following formula: 2.0 < Fno < 15.0 -0.1 < f / fx < 0.1 3.0<M<8.0 where, Fno: the F-number of the optical system f: the focal length of the entire optical system fx: the focal length of the incident surface or the optical component on which the incident surface is formed M = f / f1 f1: the focal length of the first reflecting portion.

3. The optical system according to claim 2, wherein, When observing from the direction orthogonal to the optical axis of the optical system, the reflecting surface of the first reflecting portion is arranged closer to the image plane than the emitting surface.

4. The optical system according to any one of claims 1 to 3, wherein, The optical system satisfies the condition of the following formula: 0.5 < (h1in / d1-i) / (h4 / d4-i) < 10.0 where, h1in: the inner diameter of the incident surface d1-i: the distance between the optical axis center of the incident surface and the image plane h4: the outer diameter of the emitting surface d4-i: the distance between the optical axis center of the emitting surface and the image plane.

5. The optical system according to any one of claims 1 to 3, wherein, The optical system satisfies the condition of the following formula: 0.1 < r4 / TL3 < 10.0 where, r4: the radius of curvature of the emitting surface TL3: the distance between the reflecting surface of the second reflecting portion and the image plane.

6. The optical system according to any one of claims 1 to 3, wherein, The optical system satisfies the condition of the following formula: 50.0 < νd where, νd: the Abbe number of the medium contained in the transmission component for the d-line.

7. The optical system according to any one of claims 1 to 3, wherein, The first reflecting portion and the second reflecting portion are each composed of one reflecting surface.

8. The optical system according to any one of claims 1 to 3, wherein, The optical system satisfies the condition of the following formula: f < 500 mm.

9. The optical system according to any one of claims 1 to 3, wherein, The optical axis of the reflecting surface of the first reflecting portion coincides with the optical axis of the reflecting surface of the second reflecting portion.

10. The optical system according to any one of claims 1 to 3, wherein, The optical system satisfies the condition of the following formula: 1.0 < D1 / D2 < 6.0 where, D1: the outer diameter of the reflecting surface of the first reflecting portion D2: the outer diameter of the reflecting surface of the second reflecting portion.

11. The optical system according to any one of claims 1 to 3, wherein, The optical system satisfies the condition of the following formula: 0.4 < RL / TL < 1.2 wherein, RL: The distance between the reflecting surface of the first reflecting portion and the reflecting surface of the second reflecting portion in the direction of the optical axis of the optical system TL: The distance from the surface closest to the object side of the optical system to the image plane in the direction of the optical axis of the light incident on the image plane.

12. The optical system according to any one of claims 1 to 3, wherein The optical system satisfies the condition of the following formula: 0.5 < D1 / RL < 2.0 wherein, D1: The outer diameter of the reflecting surface of the first reflecting portion RL: The distance between the reflecting surface of the first reflecting portion and the reflecting surface of the second reflecting portion in the direction of the optical axis of the optical system.

13. An optical device, comprising: The optical system according to any one of claims 1 to 12; and An imaging element that captures an image formed by the optical system.

14. The optical device according to claim 13, wherein The optical device satisfies the condition of the following formula: 5.0 < D0 / Y < 15.0 wherein, D0: The outer diameter of the incident surface closest to the object side of the optical system, Y: The maximum image height of the imaging element.

15. The optical device according to claim 13 or 14, wherein The optical device includes a plurality of the optical systems and the imaging elements respectively, The optical device includes a generation unit that generates one image based on a plurality of image signals output from the plurality of imaging elements, and the optical device satisfies the condition of the following formula: 0.30 < Nc / (Nd × n) < 1.00 wherein, Nd: The number of pixels of the imaging element n: The number of imaging elements used for generating the image Nc: The number of pixels of the image.

16. The optical device according to claim 13 or 14, wherein The optical device includes a plurality of the optical systems and the imaging elements respectively, The optical device includes a generation unit that generates one image based on a plurality of image signals output from the plurality of imaging elements, and the optical device satisfies the condition of the following formula: 0.50 < Nc / (Nd × √n) < 2.00 wherein, Nd: The number of pixels of the imaging element n: The number of imaging elements used for generating the image Nc: The number of pixels of the image.

17. The optical device according to claim 13 or 14, wherein The optical device includes: A first holding unit that integrally holds the plurality of imaging elements; and A second holding unit that integrally holds the plurality of optical systems.

18. A photographing device, wherein It includes a plurality of photographing units, and each photographing unit includes: the optical system according to any one of claims 1 to 12, which has a first reflecting surface and a second reflecting surface in sequence along the optical path from the object side to form an image of the object; and an imaging element that captures the image formed by the optical system, At least two of the imaging elements are arranged in a manner such that their relative positions in the optical axis direction with respect to the optical system are different.

19. The imaging device according to claim 18, wherein the difference in the relative positions is a value corresponding to the subject depth of the optical system.

20. The imaging device according to claim 18 or 19, wherein the relative positions of at least a part of the optical system or the imaging element in the optical axis direction are variable.

21. The imaging device according to claim 18 or 19, wherein at least one of the imaging units is arranged such that the focal plane when the imaging element and the optical system are focused at infinity or the closest distance is substantially coincident.

Images