JP6785120B2 - Lens and optical unit - Google Patents

Description

The present invention relates to a lens and an optical unit.

In an optical unit in which a lens is housed in a lens barrel, the lens and the lens barrel expand or contract in response to a temperature change, so that the lens is press-fitted into the lens barrel, and the lens press-fitted into the lens barrel has a diameter. A directional compressive force acts. Then, a difference in expansion or contraction occurs due to the difference in material between the lens and the lens barrel, and the compressive force acting on the lens increases or decreases due to the difference in expansion or contraction. The compressive force that changes in this way may cause distortion on the optical surface of the lens, for example, and the distortion on the optical surface may reduce the optical performance of the lens and the optical unit.

In the lens unit described in Patent Document 1, in the lens press-fitted into the lens barrel, a portion of 50% or more of the length of the fitting surface in the optical axis direction among the portions surrounded by the fitting surface with the lens barrel is medium. It is really formed. When the compressive force acting on the lens is applied to the fitting surface, the solid part provided in the portion surrounded by the fitting surface acts as a beam to receive the compressive force, thereby suppressing the deformation of the optical surface. There is.

Japanese Unexamined Patent Publication No. 2014-170124

Deflection of the lens is one of the main causes of distortion on the optical surface of the lens. The compressive force as the distributed load applied to the fitting surface is replaced with an equivalent concentrated load applied on the circumference that divides the fitting surface into two equal parts in the optical axis direction, and this concentrated load is applied to the fitting. The circumference on the surface shifts in the optical axis direction with respect to the center of the lens, that is, the midpoint between the intersection of one optical surface of the lens with the optical axis and the intersection of the other optical surface with the optical axis. If so, a bending moment around the center of the lens is generated. This bending moment causes the lens to bend.

In the lens of the lens unit described in Patent Document 1, the circumference on the fitting surface to which a concentrated load equivalent to the compressive force applied to the fitting surface is applied is in the optical axis direction with respect to the center of the lens. It is out of alignment. Therefore, the lens tends to bend with respect to the compressive force, and the optical surface of the lens may be distorted.

The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress distortion of the optical surface of a lens press-fitted into a lens barrel and to improve the optical performance of the lens and the optical unit.

The lens of one aspect of the present invention has an outermost peripheral surface parallel to the optical axis, a first flange surface between the outer edge of one first optical surface and one end of the outermost outer peripheral surface in the optical axis direction, and the other. A second flange surface between the outer edge of the second optical surface and the other end of the outermost peripheral surface in the optical axis direction is provided.
The plane that passes through the intersection of the optical axis and the first optical plane and is orthogonal to the optical axis is the first plane, and the plane that passes through the intersection of the optical axis and the second optical plane and is orthogonal to the optical axis is the first plane. The two surfaces are defined as a plane passing through the center between the first surface and the second surface and orthogonal to the optical axis as the lens center surface, and the lens center surface intersects the outermost outer surface of the lens. The plane passing through the point on the first flange surface farthest from the central surface in the optical axis direction and orthogonal to the optical axis is defined as the third surface, and the second flange surface farthest from the center surface of the lens in the optical axis direction. The plane passing through the upper point and orthogonal to the optical axis is defined as the fourth plane, and the plane passing through the center between the third plane and the fourth plane and orthogonal to the optical axis is defined as the flange center plane. The surface is biased toward the third surface side with respect to the central surface of the flange, the first flange surface is a flat surface having no recess, and the second flange surface is centered on the optical axis. It has an annular second flange surface side recess, and the bottom of the second flange surface side recess is arranged on the fourth surface side of the lens center surface , and the second optical surface is a concave surface. The plane passing through the bottom of the concave portion on the second flange surface side and orthogonal to the optical axis is defined as the fifth surface, and the outermost outer peripheral surface between the third surface and the fifth surface is bisected in the optical axis direction. The circumference is substantially on the central plane of the lens.
The lens of another aspect of the present invention has an outermost outer surface parallel to the optical axis, a first flange surface between the outer edge of one first optical surface and one end of the outermost outer surface in the optical axis direction, and the other. A second flange surface between the outer edge of the second optical surface and the other end of the outermost outer surface in the optical axis direction is provided, and the optical axis passes through the intersection of the optical axis and the first optical surface. The plane orthogonal to the optical axis is the first plane, the plane passing through the intersection of the optical axis and the second optical plane and orthogonal to the optical axis is the second plane, and the center between the first plane and the second plane. A plane on the first flange surface that intersects the outermost outer peripheral surface of the lens and is the farthest from the central surface of the lens in the optical axis direction, with a plane orthogonal to the optical axis as the central surface of the lens. The plane passing through and orthogonal to the optical axis is defined as the third surface, and the plane passing through the point on the second flange surface farthest from the center surface of the lens in the optical axis direction and orthogonal to the optical axis is defined as the fourth surface. The surface passing through the center between the third surface and the fourth surface and orthogonal to the optical axis is set as the flange center surface, and the lens center surface is biased toward the third surface side with respect to the flange center surface. The first flange surface has an annular first flange surface side recess centered on the optical axis, and the second flange surface has an annular second flange surface side recess centered on the optical axis. The bottom of the concave portion on the second flange surface side is arranged on the fourth surface side of the central surface of the lens, the first optical surface is a concave surface, and the second optical surface is a concave surface. The plane passing through the bottom of the recess on the second flange surface side and orthogonal to the optical axis is defined as the fifth plane, and the plane passing through the bottom of the recess on the first flange surface side and orthogonal to the optical axis is defined as the sixth plane. The circumference that bisects the outermost outer peripheral surface between the sixth surface and the fifth surface in the optical axis direction is substantially on the central surface of the lens.
Further, the optical unit according to one aspect of the present invention includes a plurality of optical elements including the lens and a lens barrel accommodating the optical element, and the lens barrel facing the outermost outer peripheral surface of the lens. The lens is press-fitted into the lens fixing portion in a state of being fitted with the entire outermost peripheral surface of the lens.

Further, the optical unit of one aspect of the present invention is an optical unit including one or more optical elements including a lens and a lens barrel accommodating the optical elements .
The lens has an outermost outer surface parallel to the optical axis, a first flange surface between the outer edge of one first optical surface and one end of the outermost outer surface in the optical axis direction, and the other second optical surface. A first plane is provided with a second flange surface between the outer edge and the other end of the outermost peripheral surface in the optical axis direction, passes through the intersection of the optical axis and the first optical surface, and is orthogonal to the optical axis. The plane is a plane that passes through the intersection of the optical axis and the second optical plane and is orthogonal to the optical axis as the second plane, passes through the center between the first plane and the second plane, and is the optical axis. With the orthogonal plane as the central surface of the lens, the central surface of the lens intersects the outermost peripheral surface of the lens, passes through the point on the first flange surface farthest from the central surface of the lens in the optical axis direction, and meets the optical axis. The plane orthogonal to the optical axis is defined as the third surface, and the plane passing through the point on the second flange surface farthest from the center surface of the lens in the optical axis direction and orthogonal to the optical axis is defined as the fourth surface. The plane passing through the center between the fourth plane and orthogonal to the optical axis is the flange center plane, and the lens center plane is biased toward the third plane with respect to the flange center plane, and the first flange The surface is a flat surface having no recess, the second flange surface has an annular second flange surface side recess centered on the optical axis, and the bottom of the second flange surface side recess is the above. The lens is fixed by using the region of the lens barrel facing the outermost peripheral surface of the lens as a lens fixing portion, which is arranged on the fourth surface side of the lens center surface and the second optical surface is a concave surface. The portion is a fitting portion in which the lens is press-fitted in a state of being fitted with a part of the outermost outer peripheral surface of the lens on the fourth surface side and intersecting with the central surface of the lens, and a fitting portion of the lens. possess a non-engaging portion facing a gap between the remainder of the third surface side of the outermost peripheral surface, the plane perpendicular to the bottom as the optical axis of the second flange surface recess The fifth surface is the surface that passes through the boundary between the fitting portion and the non-fitting portion and is orthogonal to the optical axis, and is the seventh surface, which is the outermost outer peripheral surface between the seventh surface and the fifth surface. The circumference that divides the image into two equal parts in the optical axis direction is substantially on the central surface of the lens .

According to the present invention, it is possible to suppress distortion of the optical surface of the lens press-fitted into the lens barrel and improve the optical performance of the lens and the optical unit.

It is sectional drawing of an example of an optical unit for demonstrating the embodiment of this invention. It is a detailed cross-sectional view of the lens included in the optical unit of FIG. It is a graph of an example of the surface shape change amount of the optical surface of the lens of FIG. It is sectional drawing which shows the modification of the lens of FIG. 1 in the state which was accommodated in the lens barrel. It is sectional drawing which shows the other example of the lens in the state which was housed in the lens barrel for demonstrating the embodiment of this invention. It is a graph of an example of the surface shape change amount of the optical surface of the lens of FIG. It is sectional drawing of the main part of another example of an optical unit for demonstrating the embodiment of this invention.

FIG. 1 shows an example of an optical unit for explaining an embodiment of the present invention, and FIG. 2 shows a lens included in the optical unit of FIG.

The optical unit 1 shown in FIG. 1 includes a first lens 2, a second lens 3A, a diaphragm 4, and a lens barrel 5 accommodating the first lens 2, the second lens 3A, and the diaphragm 4. .. The first lens 2 is arranged on the subject side most, the second lens 3A is arranged on the image side of the first lens 2, and the aperture 4 is arranged on the image side of the second lens 3A. The configuration such as the number of lenses and the arrangement of diaphragms is not limited to the illustrated example, and can be appropriately changed according to the design of the optical unit.

The lens barrel 5 has a first lens fixing portion 10 and a second lens fixing portion 11. The second lens fixing portion 11 is formed to have a smaller diameter than the first lens fixing portion 10, and a first step portion 12 is provided between the first lens fixing portion 10 and the second lens fixing portion 11. .. Further, a second step portion 13 is similarly provided on the image side of the second lens fixing portion 11.

The first lens 2 is inserted into the lens barrel 5 to a position where it comes into contact with the first step portion 12, and is positioned in the axial direction inside the lens barrel 5 by contacting with the first step portion 12. Then, the first lens 2 is press-fitted into the first lens fixing portion 10 in a state of being in contact with the first stage portion 12, and is fixed to the lens barrel 5 by being press-fitted into the first lens fixing portion 10. There is.

The second lens 3A is inserted into the lens barrel 5 to a position where it comes into contact with the second stage portion 13 on which the aperture 4 is placed, and the inside of the lens barrel 5 is brought into contact with the second stage portion 13 via the aperture 4. It is positioned in the axial direction with. Then, the second lens 3A is press-fitted into the second lens fixing portion 11 in a state of being in contact with the second stage portion 13, and is fixed to the lens barrel 5 by being press-fitted into the second lens fixing portion 11. There is.

The aperture 4 is positioned in the axial direction inside the lens barrel 5 and fixed to the lens barrel 5 by being sandwiched between the second lens 3A and the second stage portion 13.

As the material of the first lens 2 and the second lens 3A, for example, a resin material such as Cyclo Olefin Polymer (COP) and polymethylacrylic (PMMA), and a glass material such as quartz glass are used. Can be done.

As an example, the lens barrel 5 can be made of a resin containing an inorganic fiber. By making the lens barrel 5 made of so-called inorganic fiber reinforced plastic containing inorganic fibers and the like, the mechanical strength is increased. Examples of the resin to be used include polyamide, polyacetal, polycarbonate, polyphenylene ether, polybutylene terephthalate, polyethylene terephthalate, polyethylene, syndiotactic polystyrene, polysulfone, polyethersulfon, polyphenylene sulfide, polyarylate, polyamideimide, and polyether. A polymer alloy containing at least one selected from the group consisting of imide, polyether ether ketone, acrylonitrile budadiene styrene, polyolefin and each modified polymer, or at least one selected from the above group can be used. As the fiber, glass fiber, carbon fiber, fiber reinforced plastic, inorganic filler and the like can be used.

The lens barrel 5 is required to have high light-shielding property and light absorption property. The resin used is preferably black, and the above resin material preferably contains a black pigment or a black dye. By forming the lens barrel 5 with a resin material containing a black pigment or a black dye, the inner wall surface of the lens barrel 5 can be made black, and the reflection of visible light on the inner wall surface of the lens barrel 5 can be suppressed more effectively. be able to.

Further, it is preferable that the coefficient of thermal expansion in the optical axis direction of the lens barrel 5 is smaller than the coefficient of thermal expansion in the direction orthogonal to the optical axis. This is because the amount of change in the optical axis direction due to thermal expansion can be reduced to reduce the effect on resolution reduction. By setting the orientation direction of the fibers along the optical axis, the coefficient of thermal expansion in the direction of the optical axis can be made smaller than the coefficient of thermal expansion in the direction orthogonal to the optical axis.

A compressive force in the radial direction acts on the first lens 2 which is press-fitted into the first lens fixing portion 10 of the lens barrel 5. A compressive force in the radial direction also acts on the second lens 3A that is press-fitted into the second lens fixing portion 11 of the lens barrel 5. Then, due to the difference in materials between the first lens 2 and the second lens 3A and the lens barrel 5, the expansion or contraction of the first lens 2 and the second lens 3A and the lens barrel 5 in response to the temperature change. There is a difference between expansion and contraction, and the difference between expansion and contraction increases or decreases the compressive force acting on the first lens 2 and the second lens 3A.

By suppressing the distortion of the optical surfaces of the first lens 2 and the second lens 3A due to the compressive force changing in this way, the optical performance of each of the first lens 2 and the second lens 3A, and the optical unit 1 The optical performance of the lens can be improved. In particular, the influence of the second lens 3A adjacent to the aperture 4 on the optical performance of the optical unit 1 is relatively larger than the influence of the first lens 2 on the optical performance of the optical unit 1. That is, in order to improve the optical performance of the optical unit 1, it is effective to suppress the distortion of the optical surface of the second lens 3A. Hereinafter, the configuration of the lens for suppressing the distortion of the optical surface due to the compressive force will be described by taking the second lens 3A as an example. Of course, the lens configuration described below is also applicable to the first lens 2 which is also press-fitted into the lens barrel 5.

FIG. 2 shows a detailed configuration of the second lens 3A.

The second lens 3A includes an outermost outer peripheral surface 20A parallel to the optical axis x, a first optical surface 21 arranged on the subject side, a second optical surface 22 arranged on the image side, and a first optical surface 21. Between the first flange surface 23 between the outer edge E1 and one end E3 of the outermost outer peripheral surface 20A in the optical axis direction, and between the outer edge E2 of the second optical surface 22 and the other end E4 of the outermost outer peripheral surface 20A in the optical axis direction. It is provided with a second flange surface 24. In this example, the first optical surface 21 is formed in a convex spherical surface shape, and the second optical surface 22 is formed in a concave spherical surface shape. The combination of the shapes of the first optical surface 21 and the second optical surface 22 is not particularly limited, and an appropriate combination of a convex spherical surface, a concave spherical surface, an aspherical surface, and a flat surface can be taken depending on the design of the optical unit 1. ..

The outermost outer peripheral surface 20A is a surface that fits into the second lens fixing portion 11 of the lens barrel 5 in the optical unit 1 shown in FIG. The second lens fixing portion 11 as a region of the lens barrel 5 facing the outermost outer peripheral surface 20A is formed to have a constant inner diameter over the entire length in the axial direction, and the outermost outer peripheral surface 20A is the second over the entire length in the optical axis direction. The compressive force that fits into the lens fixing portion 11 and acts on the second lens 3A is applied to the entire outermost peripheral surface 20A.

The midpoint between the intersection P1 of the first optical surface 21 with the optical axis x and the intersection P2 of the second optical surface 22 with the optical axis x is the center O of the second lens 3A, and the second lens 3A has the highest point. The bending moment around the center O due to the compressive force applied to the outer peripheral surface 20A is suppressed. As a result, the deflection of the second lens 3A is suppressed, and the distortion of the first optical surface 21 and the second optical surface 22 is suppressed.

Then, the compressive force as the distributed load applied to the outermost outer peripheral surface 20A is replaced with an equivalent concentrated load applied to the circumference C1 that divides the outermost outer peripheral surface 20A into two equal parts in the optical axis direction, and this concentrated load is generated. The bending moment around the center O is suppressed by reducing the deviation of the loaded circumference C1 and the center O in the optical axis direction.

First, the plane that passes through the intersection P1 of the first optical surface 21 with the optical axis x and is orthogonal to the optical axis x is defined as the first surface S1, and passes through the intersection P2 of the second optical surface 22 with the optical axis x and becomes the optical axis x. The plane orthogonal to the second plane S2 is defined as the second plane S2, and the plane passing through the center between the first plane S1 and the second plane S2 and orthogonal to the optical axis x, that is, the plane passing through the center O and orthogonal to the optical axis x is the lens center plane. As SS1, the lens center surface SS1 intersects the outermost outer peripheral surface 20A.

Further, the plane passing through the point on the first flange surface 23 farthest from the lens center surface SS1 in the optical axis direction and orthogonal to the optical axis x is defined as the third surface S3, and is farthest from the lens center surface SS1 in the optical axis direction. The plane passing through the point on the second flange surface 24 and orthogonal to the optical axis x is defined as the fourth surface S4, and the plane passing through the center between the third surface S3 and the fourth surface S4 and orthogonal to the optical axis x is the flange center. As the surface SS2, the lens center surface SS1 is biased toward the third surface S3 with respect to the flange center surface SS2.

The amount of deviation Δ between the circumference C1 and the center O in the optical axis direction is at least smaller than the amount of deviation of the lens center surface SS1 with respect to the flange center surface SS2. Then, since the lens center surface SS1 passing through the center O intersects the outermost outer peripheral surface 20A, for example, the circumference C1 is such that the position on the optical axis of the circumference C1 substantially coincides with the position of the center O. It is possible to reduce the amount of deviation Δ between the lens and the center O in the optical axis direction. Hereinafter, a configuration for reducing the amount of deviation Δ between the circumference C1 and the center O in the optical axis direction will be described.

The first flange surface 23 is provided in the range from the third surface S3 to the first surface S1. The range from the third surface S3 to the first surface S1 includes the third surface S3 and the first surface S1. In this example, the first optical surface 21 that provides the intersection P1 through which the first surface S1 passes is formed in a convex spherical shape, and the third surface S3 is the first flange farthest from the lens center surface SS1 in the optical axis direction. Since it is a flat surface passing through a point on the surface 23, the first flange surface 23 is included in the third surface S3 and is a flat surface having no recess.

On the other hand, the second flange surface 24 has an annular second flange surface side recess 25A centered on the optical axis x. The bottom 26 of the second flange surface side recess 25A is arranged on the fourth surface S4 side of the lens center surface SS1. The bottom of the recess on the second flange surface side means the light passing through the point on the second flange surface 24 which is the farthest from the lens center surface SS1 in the optical axis direction among the recesses on the second flange surface side. It is defined as the portion farthest from the plane (plane orthogonal to the axis x) in the optical axis direction. In this example, the second flange surface side recess 25A is configured as a chamfered portion provided along the outer edge of the second flange surface 24, and the bottom 26 of the second flange surface side recess 25A is the outermost outer peripheral surface 20A. It coincides with one end E4 on the fifth surface S5 side.

Assuming that the second flange surface side recess 25A is not provided on the second flange surface 24, the outermost outer peripheral surface of the second lens 3A is provided so as to straddle the third surface S3 to the fourth surface S4. Therefore, when the compressive force applied to the outermost peripheral surface is replaced with an equivalent concentrated load applied to the circumference that bisects the outermost peripheral surface in the optical axis direction, the circumference on which this concentrated load is applied. Is arranged on the flange center surface SS2.

On the other hand, when the second flange surface side recess 25A is provided on the second flange surface 24, the second flange surface side recess 25A is the second circumferential C1 on the outermost outer peripheral surface 20A and the outermost outer peripheral surface 20A. 2 It is closer to the third surface S3 side as compared with the case where it is not provided on the flange surface 24. As a result, the amount of deviation Δ between the circumference C1 and the center O in the optical axis direction becomes smaller than the amount of deviation of the lens center surface SS1 with respect to the flange center surface SS2.

Then, by appropriately adjusting the position of the bottom 26 of the second flange surface side recess 25A in the optical axis direction, for example, the position of the circumference C1 on the optical axis substantially coincides with the position of the center O. The amount of deviation Δ between the circumference C1 and the center O in the optical axis direction can be reduced. As a result, the bending moment around the center O due to the compressive force applied to the outermost peripheral surface 20A can be suppressed, and the bending of the second lens 3A can be suppressed, resulting in distortion of the first optical surface 21 and the second optical surface 22. Can be suppressed.

In this example, the second optical surface 22 is formed in a concave spherical shape, and the lens in which at least one optical surface is concave in this way is structurally subjected to a radial compressive force applied to the outermost peripheral surface. Due to this, it is easy to bend. The configuration of the second lens 3A described above is particularly useful for suppressing bending of a lens in which at least one optical surface is concave.

As described above, the optical unit 1 in which the bending of the second lens 3A is suppressed is suitable as an optical unit for in-vehicle use or monitoring. The in-vehicle or surveillance optical unit is used in an environment exposed to a relatively high temperature, and the difference in expansion between the lens and the lens barrel is relatively large, and the compression applied to the lens press-fitted into the lens barrel is applied. The force is also relatively large. However, according to the optical unit 1, the bending moment around the center O caused by the compressive force applied to the second lens 3A is suppressed, so that the bending of the second lens 3A is suppressed, and thereby the high temperature. The optical performance of the optical unit 1 can be maintained even when exposed to.

From the viewpoint of suppressing the bending moment around the center O, it is preferable that the position of the circumference C1 on the optical axis substantially coincides with the position of the center O. The fact that the position of the circumference C1 on the optical axis substantially coincides with the position of the center O means that the bending moment is suppressed to the extent that the bending of the second lens 3A based on the bending moment around the center O can be ignored. In the range, a slight deviation between the circumference C1 and the center O in the optical axis direction is included, and specifically, it means that the following equation is satisfied.
| D3 × 0.5-D2 | ≦ D1 × 0.10 ... (1)

Here, the plane passing through the bottom 26 of the second flange surface side recess 25A and orthogonal to the optical axis x is defined as the fifth surface S5, and D1 of the equation (1) is between the first surface S1 and the second surface S2. D2 is the distance between the fifth surface S5 and the lens center surface SS1, and D3 is the distance between the fifth surface S5 and the third surface S3. The left side | D3 × 0.5-D2 | of the equation (1) corresponds to the amount of deviation Δ between the circumference C1 and the center O in the optical axis direction.

FIG. 3 shows the relationship between the displacement amount Δ (| D3 × 0.5−D2 |) of the second lens 3A and the surface shape change amount ω of the first optical surface 21.

Let Y be the radial distance from the optical axis x, and the amount of displacement in the optical axis direction at the point of the distance Y on the first optical surface 21 between the no-load state and the state in which the outermost peripheral surface 20A is loaded with a compressive force. Is the surface shape change amount ω (Y), and the surface shape change amount ω (Y) is proportional to the square of the deviation amount Δ and the distance Y and inversely proportional to β, as shown in the following equation.
ω (Y) = Δ ・ f (Y ^ 2) ・ 1 / β ・ ・ ・ (i)
Note that β is the rigidity coefficient of the second lens 3A, and the rigidity coefficient β is a variable that depends on the shape of the lens (convex or concave, curvature, etc.), and 0 <β ≦ 1. The unit of the surface shape change amount ω is micron meter, and the unit of the deviation amount Δ and the distance Y is millimeter.

In the graph shown in FIG. 3, the second lens 3A is made of a resin material, the first optical surface 21 has an outer diameter of φ5 mm, and the outermost peripheral surface is in consideration of a general optical unit for in-vehicle use or monitoring. Based on the equation (i), the surface shape change amount ω in a plurality of deviation amounts Δ is calculated by calculating the distributed load applied to the circumference C1 equivalent to the compressive force applied to 20A as 4.4 MPa. is there.

As can be seen from FIG. 3, when the deviation amount Δ is D1 × 0.10 or less, the surface shape change amount ω is within 1 μm even at the outermost peripheral portion of the first optical surface 21, and the surface shape change of the first optical surface 21 The optical performance of the second lens 3A can also be maintained.

FIG. 4 shows a modified example of the second lens 3A described above.

In the second lens 3B shown in FIG. 4, a second flange surface side recess 25B configured as a groove is provided on the second flange surface 24 in place of the second flange surface side recess 25A configured as a chamfered portion. There is. As the second flange surface side recess 25B is formed as a groove, the outermost outer peripheral surface 20B of the second lens 3B is provided so as to straddle the third surface S3 to the fourth surface S4.

Of the outermost outer peripheral surface 20B, compression is performed on both the overlapping region 20Ba that is radially superimposed on the second flange surface side recess 25B and the non-overlapping region 20Bb that is not radially superimposed on the second flange surface side recess 25B. Although a force is applied, most of the compressive force applied to the overlapping region 20Ba is absorbed by the deformation of the second flange surface side recess 25B formed as a groove, and the deflection of the second lens 3B is reduced. It is mainly dominated by the compressive force applied to the non-superimposed region 20Bb.

Therefore, in relation to the deflection of the second lens 3B, the compressive force applied to the non-superimposed region 20Bb is converted to an equivalent concentrated load applied to the circumference C2 that bisects the non-superimposed region 20Bb in the optical axis direction. By replacing it, the deviation in the optical axis direction between the circumference C2 on which this concentrated load is applied and the center O may be reduced. Then, by appropriately adjusting the position of the bottom 26 of the second flange surface side recess 25B in the optical axis direction, for example, the position of the circumference C2 on the optical axis substantially coincides with the position of the center O. The amount of deviation Δ between the circumference C2 and the center O in the optical axis direction can be reduced. As a result, the bending moment around the center O due to the compressive force applied to the outermost peripheral surface 20B can be suppressed, and the bending of the second lens 3B can be suppressed, resulting in distortion of the first optical surface 21 and the second optical surface 22. Can be suppressed.

Further, in this example, since the second flange surface side recess 25B is configured as a groove, the outermost outer peripheral surface 20B is provided so as to straddle the third surface S3 to the fourth surface S4, and is shown in FIG. It is extended in the optical axis direction from the outermost outer peripheral surface 20A of the second lens 3A. As a result, the fitting allowance between the outermost outer peripheral surface 20B and the second lens fixing portion 11 of the lens barrel 5 is extended, and the second lens 3B press-fitted into the lens barrel 5 collapses, that is, the second lens 3B with respect to the central axis of the lens barrel 5. The inclination of the optical axis x of the two lenses 3B can be suppressed, and the optical performance of the optical unit can be further improved.

From the viewpoint of suppressing the bending moment around the center O, the position of the circumference C2 on the optical axis substantially coincides with the position of the center O, and specifically, it is preferable that the equation (1) is satisfied. However, the fifth surface S5 that defines the distance D3 in the formula (1) is a plane that passes through the bottom 26 of the second flange surface side recess 25B and is orthogonal to the optical axis x. Further, since the second flange surface side recess 25B is configured as a groove, the flange portion of the second lens 3B (the portion sandwiched by the first flange surface 23 and the second flange surface 24 in the optical axis direction) is formed. A constriction is formed. From the viewpoint of suppressing the decrease in the strength of the flange portion due to this constriction, the bottom 26 of the second flange surface side recess 25B is arranged on the second surface S2 or on the fourth surface S4 side of the second surface S2. It is preferable to have.

In the illustrated example, the bottom 26 of the second flange surface side recess 25B is different from the fourth surface S4 side with the second surface S2 in between so that the position of the circumference C2 on the optical axis coincides with the position of the center O. Although it is arranged on the opposite side, the position of the bottom 26 of the second flange surface side recess 25B in the optical axis direction may be adjusted in a balance between suppressing the bending moment around the center O and ensuring the strength of the flange portion. ..

In the second lens 3A and the second lens 3B described above, the recess is provided only on one flange surface (second flange surface 24), but the recess may be provided on both flange surfaces of the lens. Hereinafter, a case where recesses are provided on both flange surfaces of the lens will be described with reference to FIG.

FIG. 5 shows another example of a lens for explaining an embodiment of the present invention.

The lens 103 shown in FIG. 5 is a lens used as one of a plurality of optical elements of the optical unit, and is fixed to the lens barrel 105 by being press-fitted into the lens fixing portion 111 of the lens barrel 105.

The lens 103 has an outermost outer peripheral surface 120 parallel to the optical axis x, a first optical surface 121 arranged on the subject side, a second optical surface 122 arranged on the image side, and an outer edge E1 of the first optical surface 121. The first flange surface 123 between the outermost outer peripheral surface 120 and one end E3 in the optical axis direction, and the second outer edge E2 of the second optical surface 122 and the other end E4 in the optical axis direction of the outermost outer peripheral surface 120. A flange surface 124 is provided, and both the first optical surface 121 and the second optical surface 122 are formed in a concave spherical shape.

The plane that passes through the intersection P1 of the first optical surface 121 with the optical axis x and is orthogonal to the optical axis x is defined as the first plane S1, and passes through the intersection P2 of the second optical surface 122 with the optical axis x and is orthogonal to the optical axis x. The plane is defined as the second surface S2, and the plane passing through the center between the first surface S1 and the second surface S2 and orthogonal to the optical axis x, that is, the plane passing through the center O and orthogonal to the optical axis x is defined as the lens center surface SS1. , The central surface SS1 of the lens intersects the outermost surface 120.

Further, the plane passing through the point on the first flange surface 123 farthest from the lens center surface SS1 in the optical axis direction and orthogonal to the optical axis x is defined as the third surface S3, and is farthest from the lens center surface SS1 in the optical axis direction. The plane passing through the point on the second flange surface 124 and orthogonal to the optical axis x is defined as the fourth surface S4, and the plane passing through the center between the third surface S3 and the fourth surface S4 and orthogonal to the optical axis x is the flange center. As the surface SS2, the lens center surface SS1 is biased toward the third surface S3 with respect to the flange center surface SS2.

The first flange surface 123 has an annular first flange surface side recess 127 centered on the optical axis x, and includes the first flange surface side recess 127 from the third surface S3 to the first surface S1. It is provided in the range. That is, the bottom 128 of the first flange surface side recess 127 is arranged on the first surface S1 or on the third surface S3 side of the first surface S1. The first flange surface side recess 127 may be configured as a chamfered portion provided along the outer edge of the first flange surface 123, but in this example, it is configured as a groove.

The second flange surface 124 also has an annular second flange surface side recess 125 centered on the optical axis x, and the bottom 126 of the second flange surface side recess 125 is a fourth surface S4 rather than the lens center surface SS1. It is located on the side. The second flange surface side recess 125 may be configured as a chamfered portion provided along the outer edge of the second flange surface 124, but in this example, it is configured as a groove.

The lens fixing portion 111 of the lens barrel 105 is formed to have a constant inner diameter over the entire length in the axial direction, and the outermost outer peripheral surface 120 fits into the lens fixing portion 111 over the entire length in the optical axis and acts on the lens 103. The compressive force to be applied is the entire outermost peripheral surface 120, that is, the first overlapping region 120a that is radially superimposed on the first flange surface side recess 127, and the second that is radially superimposed on the second flange surface side recess 125. The load is applied to both the overlapping region 120b, the first flange surface side recess 127, the second flange surface side recess 125, and the non-superimposing region 120c which is not superposed in the radial direction. However, the deflection of the lens 103 is mainly dominated by the compressive force applied to the non-overlapping region 120c.

Therefore, in relation to the deflection of the lens 103, the compressive force applied to the non-overlapping region 120c is replaced with an equivalent concentrated load applied to the circumference C3 that bisects the non-overlapping region 120c in the optical axis direction. , The deviation in the optical axis direction between the circumference C3 on which this concentrated load is applied and the center O may be reduced. Then, by appropriately adjusting the positions of the bottom 128 of the first flange surface side recess 127 and the bottom 126 of the second flange surface side recess 125 in the optical axis direction, for example, the position on the optical axis of the circumference C3 is the center. The amount of deviation Δ between the circumference C3 and the center O in the optical axis direction can be reduced so as to substantially coincide with the position of O. As a result, the bending moment around the center O due to the compressive force applied to the outermost peripheral surface 120 can be suppressed, and thus the bending of the lens 103 is suppressed to suppress the distortion of the first optical surface 121 and the second optical surface 122. it can. The optical unit including the lens 103 whose deflection is suppressed in this way is suitable as an in-vehicle or monitoring optical unit, like the above-mentioned optical unit 1.

From the viewpoint of suppressing the bending moment around the center O, the position of the circumference C3 on the optical axis substantially coincides with the position of the center O, and specifically, it is preferable that the following equation is satisfied.
| D4 × 0.5-D2 | ≦ D1 × 0.10 ... (2)

Here, the plane passing through the bottom 126 of the second flange surface side recess 125 and orthogonal to the optical axis x is defined as the fifth surface S5, and the plane passing through the bottom 128 of the first flange surface side recess 127 and orthogonal to the optical axis x is the second plane. 6 planes S6, D1 of the equation (2) is the distance between the first plane S1 and the second plane S2, and D2 is the distance between the fifth plane S5 and the lens center plane SS1. D4 is the distance between the fifth surface S5 and the sixth surface S6. The left side | D4 × 0.5-D2 | of the equation (2) corresponds to the amount of deviation Δ between the circumference C3 and the center O in the optical axis direction.

FIG. 6 shows the relationship between the deviation amount Δ (| D4 × 0.5−D2 |) of the lens 103 shown in FIG. 5 and the surface shape change amount ω of the first optical surface 121.

Let Y be the radial distance from the optical axis x, and the amount of displacement in the optical axis direction at the point of the distance Y on the first optical surface 121 between the no-load state and the state in which the outermost peripheral surface 120 is loaded with a compressive force. Is the surface shape change amount ω (Y), and the surface shape change amount ω (Y) is proportional to the square of the deviation amount Δ and the distance Y and inversely proportional to β, as shown in the following equation.
ω (Y) = Δ ・ f (Y ^ 2) ・ 1 / β ・ ・ ・ (ii)
Note that β is the rigidity coefficient of the lens 103, and the rigidity coefficient β is a variable that depends on the shape of the lens (convex or concave, curvature, etc.), and 0 <β ≦ 1. The unit of the surface shape change amount ω is micron meter, and the unit of the deviation amount Δ and the distance Y is millimeter.

In the graph shown in FIG. 6, it is assumed that the lens 103 is made of a resin material, the first optical surface 121 has an outer diameter of φ3.5 mm, and the outermost outer peripheral surface in consideration of a general optical unit for in-vehicle use or monitoring. Based on the equation (ii), the surface shape change amount ω in a plurality of deviation amounts Δ is calculated by calculating the distributed load applied to the circumference C3 equivalent to the compressive force applied to 120 as 5.0 MPa. is there.

As can be seen from FIG. 6, when the deviation amount Δ is D1 × 0.10 or less, the surface shape change amount ω is within 1 μm even at the outermost peripheral portion of the first optical surface 121, and the surface shape change of the first optical surface 121 The optical performance of the lens 103 can also be maintained.

Since the second flange surface side recess 125 is configured as a groove, the flange portion of the lens 103 (the portion sandwiched by the first flange surface 123 and the second flange surface 124 in the optical axis direction) is constricted. Although it is formed, the bottom 126 of the second flange surface side recess 125 is formed on the second surface S2 or on the fourth surface S4 rather than on the second surface S2 from the viewpoint of suppressing the decrease in the strength of the flange portion due to this constriction. It is preferably arranged on the side.

The same applies to the first flange surface side recess 127 configured as a groove. In this example, the bottom 128 of the first flange surface side recess 127 is in the range from the third surface S3 to the first surface S1, that is, the first surface S1. It is arranged on the first surface or on the third surface S3 side of the first surface S1, and the strength of the flange portion is secured.

Up to this point, the case where recesses are provided on one flange surface of the lens or both flange surfaces and the bending moment around the center O is suppressed by the lens alone has been described, but the outermost peripheral surface of the lens and the lens of the lens barrel are fixed. It is also possible to suppress the bending moment around the center O by utilizing the fitting with the portion. Hereinafter, a case where the bending moment around the center O is suppressed by utilizing the fitting between the outermost peripheral surface of the lens and the lens fixing portion of the lens barrel will be described with reference to FIG. 7.

FIG. 7 shows key parts of other examples of optical units for explaining embodiments of the present invention.

The lens 203 shown in FIG. 7 is a lens used as one of a plurality of optical elements of the optical unit, and is fixed to the lens barrel 205 by being press-fitted into the lens fixing portion 211 of the lens barrel 205.

The lens 203 has an outermost outer peripheral surface 220 parallel to the optical axis x, a first optical surface 221 arranged on the subject side, a second optical surface 222 arranged on the image side, and an outer edge E1 of the first optical surface 221. The first flange surface 223 between the outermost outer peripheral surface 220 and one end E3 in the optical axis direction, and the second outer edge E2 of the second optical surface 222 and the other end E4 in the optical axis direction of the outermost outer peripheral surface 220. It includes a flange surface 224, and both the first optical surface 221 and the second optical surface 222 are formed in a concave spherical shape. In the lens 203, the first flange surface 223 is a flat surface having no recess on the first flange surface side, and the lens 203 and the lens 103 shown in FIG. 5 differ in the presence or absence of the recess on the first flange surface side. The other configurations are the same.

The lens fixing portion 211 of the lens barrel 205 is a fitting portion in which the lens 203 is press-fitted and intersects with the lens center surface SS1 in a state where the lens 203 is fitted with a part of the outermost outer peripheral surface 220 of the lens 203 on the fourth surface S4 side. The lens 203 has a non-fitting portion 215 facing the outermost peripheral surface 220 of the lens 203 with a gap between the remaining portion on the third surface S3 side. Therefore, the compressive force acting on the lens 203 is applied to the fitting region 220a of the outermost peripheral surface 220 that is fitted to the fitting portion 214 of the lens fixing portion 211.

Then, the compressive force applied to the fitting region 220a of the outermost outer peripheral surface 220 is radially overlapped with the second flange surface side recess 225 and the overlapping region 220b and the second flange surface side recess 225. Although it is loaded on any of the non-superimposed regions 220c, as described above, the deflection of the lens 203 is mainly dominated by the compressive force applied to the non-superimposed region 220c.

Therefore, in relation to the deflection of the lens 203, the compressive force applied to the non-overlapping region 220c is replaced with an equivalent concentrated load applied to the circumference C4 that bisects the non-overlapping region 220c in the optical axis direction. , The deviation in the optical axis direction between the circumference C4 on which this concentrated load is applied and the center O may be reduced. Then, by appropriately adjusting the position of the bottom 226 of the second flange surface side recess 225 in the optical axis direction and the ratio of the lengths of the fitted portion 214 and the non-fitting portion 215 of the lens barrel 205 in the optical axis direction, respectively. For example, the amount of deviation Δ between the circumference C4 and the center O in the optical axis direction can be reduced so that the position of the circumference C4 on the optical axis substantially coincides with the position of the center O. As a result, the bending moment around the center O due to the compressive force applied to the outermost peripheral surface 220 can be suppressed, and thus the bending of the lens 203 is suppressed to suppress the distortion of the first optical surface 221 and the second optical surface 222. it can. The optical unit including the lens 203 whose deflection is suppressed in this way is suitable as an in-vehicle or monitoring optical unit, like the above-mentioned optical unit 1.

From the viewpoint of suppressing the bending moment around the center O, the position of the circumference C4 on the optical axis substantially coincides with the position of the center O, and specifically, it is preferable that the following equation is satisfied.
| D5 × 0.5-D2 | ≦ D1 × 0.10 ... (3)

Here, the plane passing through the bottom 226 of the second flange surface side recess 225 and orthogonal to the optical axis x is defined as the fifth surface S5, passing through the boundary between the fitted portion 214 and the non-fitting portion 215 and orthogonal to the optical axis x. With the surface as the seventh surface S7, D1 in the equation (3) is the distance between the first surface S1 and the second surface S2, and D2 is the distance between the fifth surface S5 and the lens center surface SS1. And D5 is the distance between the fifth plane S5 and the seventh plane S7. Then, the left side | D5 × 0.5-D2 | of the equation (3) corresponds to the deviation amount Δ in the optical axis direction between the circumference C4 and the center O.

As described above, the lens disclosed in the present specification has a first outer peripheral surface parallel to the optical axis, a first outer edge of one of the first optical surfaces and one end of the outermost outer peripheral surface in the optical axis direction. A second flange surface between the flange surface and the outer edge of the other second optical surface and the other end of the outermost outer surface in the optical axis direction is provided, and the intersection of the optical axis and the first optical surface is provided. As shown, the plane orthogonal to the optical axis is defined as the first plane, the plane passing through the intersection of the optical axis and the second optical plane and orthogonal to the optical axis is defined as the second plane, and the first plane and the second plane are defined as the second plane. With the plane passing through the center between the two and orthogonal to the optical axis as the lens center plane, the lens center plane intersects the outermost outer peripheral plane, and is the farthest from the lens center plane in the optical axis direction. The plane passing through the point on the flange surface and orthogonal to the optical axis is defined as the third surface, and the plane passing through the point on the second flange surface farthest from the center surface of the lens in the optical axis direction and orthogonal to the optical axis is defined as the third surface. The fourth surface is the surface that passes through the center between the third surface and the fourth surface and is orthogonal to the optical axis, and the lens center surface is the third surface with respect to the flange center surface. It is biased to the side, the first flange surface is provided in the range from the third surface to the first surface, and the second flange surface is an annular second surface centered on the optical axis. It has a concave portion on the flange surface side, and the bottom of the concave portion on the second flange surface side is arranged on the fourth surface side of the central surface of the lens.

Further, in the lens disclosed in the present specification, the recess on the second flange surface side is a groove.

Further, in the lens disclosed in the present specification, the second optical surface is a concave surface, and the bottom of the recess on the second flange surface side is on the second surface or on the fourth surface side of the second surface. It is located in.

Further, the lens disclosed in the present specification has a plane that passes through the bottom of the recess on the second flange surface side and is orthogonal to the optical axis as the fifth surface, and the distance between the first surface and the second surface. Is D1, the distance between the fifth surface and the center surface of the lens is D2, and the distance between the fifth surface and the third surface is D3, and the following equation is satisfied.
| D3 × 0.5-D2 | ≦ D1 × 0.10

Further, in the lens disclosed in the present specification, the first flange surface has an annular first flange surface side recess centered on the optical axis.

Further, in the lens disclosed in the present specification, at least one of the first flange surface side recess and the second flange surface side recess is a groove.

Further, the lens disclosed in the present specification has a plane that passes through the bottom of the recess on the second flange surface side and is orthogonal to the optical axis as the fifth surface, and passes through the bottom of the recess on the first flange surface side and the optical axis. The plane orthogonal to the sixth plane is the sixth plane, the distance between the first plane and the second plane is D1, the distance between the fifth plane and the center plane of the lens is D2, and the fifth plane is the fifth plane. The following equation is satisfied, where D4 is the distance between the lens and the sixth surface.
| D4 × 0.5-D2 | ≦ D1 × 0.10

Further, the optical unit disclosed in the present specification includes one or more optical elements including the lens and a lens barrel accommodating the optical elements, and faces the outermost outer peripheral surface of the lens. With the region of the lens barrel as the lens fixing portion, the lens fixing portion is press-fitted with the lens in a state of being fitted with a part of the outermost outer peripheral surface of the lens on the fourth surface side, and the lens center. It has a fitting portion that intersects the surface and a non-fitting portion that faces the outermost outer surface of the lens with a gap between the remaining portion on the third surface side.

Further, the optical unit disclosed in the present specification has a plane that passes through the bottom of the recess on the second flange surface side and is orthogonal to the optical axis as the fifth surface, and is a boundary between the fitted portion and the non-fitted portion. The surface orthogonal to the optical axis is defined as the seventh surface, the distance between the first surface and the second surface is defined as D1, and the distance between the fifth surface and the lens center surface is defined as D2. , The distance between the fifth surface and the seventh surface is D5, and the following equation is satisfied.
| D5 × 0.5-D2 | ≦ D1 × 0.10

Further, the optical unit disclosed in the present specification includes a plurality of optical elements including the lens and a lens barrel accommodating the optical elements, and the mirror facing the outermost outer peripheral surface of the lens. With the region of the cylinder as the lens fixing portion, the lens fixing portion is press-fitted with the lens in a state of being fitted with the entire outermost peripheral surface of the lens.

Further, in the optical unit disclosed in the present specification, the optical element includes a diaphragm, and the lens is adjacent to the diaphragm.

Further, the optical unit disclosed in the present specification is for in-vehicle use or for monitoring.

1 Optical unit 2 1st lens 3A 2nd lens 3B 2nd lens 5 Lens barrel 10 1st lens fixing part 11 2nd lens fixing part 12 1st stage part 13 2nd stage part 20A Outermost outer surface 20B Outermost outer surface 20Ba Superimposition Region 20Bb Non-overlapping region 21 First optical surface 22 Second optical surface 23 First flange surface 24 Second flange surface 25A Second flange surface side recess 25B Second flange surface side recess 26 Bottom of second flange surface side recess 103 Lens 105 Lens barrel 111 Lens fixing portion 120 Outermost peripheral surface 120a First superimposing area 120b Second superimposing area 120c Non-superimposing area 121 First optical surface 122 Second optical surface 123 First flange surface 124 Second flange surface 125 Second flange surface Side recess 126 Bottom of second flange surface side recess 127 First flange surface side recess 128 Bottom of first flange surface side recess 203 Lens 205 Lens tube 211 Lens fixing part 214 Fitting part 215 Non-fitting part 220 Outermost outer surface 220a Fitting area 220b Overlapping area 220c Non-overlapping area 221 First optical surface 222 Second optical surface 223 First flange surface 224 Second flange surface 225 Second flange surface side recess 226 Bottom of second flange surface side recess C1, C2 C3, C4 Circumference D1, D2, D3 Distance E1 Outer edge of the first optical surface E2 Outer edge of the second optical surface E3 One end of the outermost outer surface in the optical axis direction E4 The other end of the outermost outer surface in the optical axis direction O Center P1 First 1 Intersection point with the optical axis of the optical surface P2 Intersection point with the optical axis of the second optical surface S1 First surface S2 Second surface S3 Third surface S4 Fourth surface S5 Fifth surface S6 Sixth surface S7 Seventh surface SS1 Lens Center surface SS2 Flange center surface x optical axis Δ deviation amount

Claims (15)

The outermost surface parallel to the optical axis,
A first flange surface between the outer edge of one of the first optical surfaces and one end of the outermost peripheral surface in the optical axis direction,
A second flange surface between the outer edge of the other second optical surface and the other end of the outermost peripheral surface in the optical axis direction,
With
The plane that passes through the intersection of the optical axis and the first optical surface and is orthogonal to the optical axis is the first plane, and the plane that passes through the intersection of the optical axis and the second optical surface and is orthogonal to the optical axis is the first plane. The two surfaces are defined as a plane passing through the center between the first surface and the second surface and orthogonal to the optical axis as the lens center surface, and the lens center surface intersects the outermost outer surface.
The third plane is a plane that passes through a point on the first flange surface that is farthest from the lens center plane in the optical axis direction and is orthogonal to the optical axis, and the second plane that is farthest from the lens center plane in the optical axis direction. The plane passing through a point on the flange surface and orthogonal to the optical axis is defined as the fourth surface, and the plane passing through the center between the third surface and the fourth surface and orthogonal to the optical axis is defined as the flange center surface. The central surface of the lens is biased toward the third surface with respect to the central surface of the flange.
The first flange surface is a flat surface having no recess, and is a flat surface .
The second flange surface has an annular second flange surface side recess centered on the optical axis.
The bottom of the recess on the second flange surface side is arranged on the fourth surface side of the lens center surface .
The second optical surface is a concave surface.
The plane passing through the bottom of the concave portion on the second flange surface side and orthogonal to the optical axis is defined as the fifth surface, and the outermost peripheral surface between the third surface and the fifth surface is bisected in the optical axis direction. The circumference is a lens substantially on the central plane of the lens. The lens according to claim 1 .
The distance between the first surface and the second surface is D1, the distance between the fifth surface and the lens center surface is D2, and the distance between the fifth surface and the third surface. Is D3, and a lens that satisfies the following formula.
| D3 × 0.5-D2 | ≦ D1 × 0.10 The lens according to claim 1 or 2 .
The concave portion on the second flange surface side is a lens having a groove. The lens according to any one of claims 1 to 3 .
The bottom of the recess on the second flange surface side is a lens arranged on the second surface or on the fourth surface side of the second surface. The outermost surface parallel to the optical axis,
A first flange surface between the outer edge of one of the first optical surfaces and one end of the outermost peripheral surface in the optical axis direction,
A second flange surface between the outer edge of the other second optical surface and the other end of the outermost peripheral surface in the optical axis direction,
With
The plane that passes through the intersection of the optical axis and the first optical surface and is orthogonal to the optical axis is the first plane, and the plane that passes through the intersection of the optical axis and the second optical surface and is orthogonal to the optical axis is the first plane. The two surfaces are defined as a plane passing through the center between the first surface and the second surface and orthogonal to the optical axis as the lens center surface, and the lens center surface intersects the outermost outer surface.
The third plane is a plane that passes through a point on the first flange surface that is farthest from the lens center plane in the optical axis direction and is orthogonal to the optical axis, and the second plane that is farthest from the lens center plane in the optical axis direction. The plane passing through a point on the flange surface and orthogonal to the optical axis is defined as the fourth surface, and the plane passing through the center between the third surface and the fourth surface and orthogonal to the optical axis is defined as the flange center surface. The central surface of the lens is biased toward the third surface with respect to the central surface of the flange.
The first flange surface has an annular first flange surface side recess centered on the optical axis.
The second flange surface has an annular second flange surface side recess centered on the optical axis.
The bottom of the recess on the second flange surface side is arranged on the fourth surface side of the lens center surface.
The first optical surface is a concave surface.
The second optical surface is a concave surface.
The plane passing through the bottom of the second flange surface side recess and orthogonal to the optical axis is defined as the fifth surface, and the plane passing through the bottom of the first flange surface side recess and orthogonal to the optical axis is defined as the sixth surface. The circumference that divides the outermost outer peripheral surface between the six surfaces and the fifth surface into two equal parts in the optical axis direction is a lens that is substantially on the central surface of the lens. The lens according to claim 5 .
The distance between the first surface and the second surface is D1, the distance between the fifth surface and the lens center surface is D2, and the distance between the fifth surface and the sixth surface. Is D4, and a lens that satisfies the following formula.
| D4 × 0.5-D2 | ≦ D1 × 0.10 The lens according to claim 5 or 6 .
A lens in which at least one of the first flange surface side recess and the second flange surface side recess is a groove. The lens according to any one of claims 5 to 7.
The bottom of the recess on the first flange surface side is arranged on the first surface or on the third surface side of the first surface.
The bottom of the recess on the second flange surface side is a lens arranged on the second surface or on the fourth surface side of the second surface. With one or more optics, including a lens ,
The lens barrel containing the optical element and
It is an optical unit equipped with
The lens is
The outermost surface parallel to the optical axis,
A first flange surface between the outer edge of one of the first optical surfaces and one end of the outermost peripheral surface in the optical axis direction,
A second flange surface between the outer edge of the other second optical surface and the other end of the outermost peripheral surface in the optical axis direction,
With
The plane that passes through the intersection of the optical axis and the first optical surface and is orthogonal to the optical axis is the first plane, and the plane that passes through the intersection of the optical axis and the second optical surface and is orthogonal to the optical axis is the first plane. The two surfaces are defined as a plane passing through the center between the first surface and the second surface and orthogonal to the optical axis as the lens center surface, and the lens center surface intersects the outermost outer surface.
The third plane is a plane that passes through a point on the first flange surface that is farthest from the lens center plane in the optical axis direction and is orthogonal to the optical axis, and the second plane that is farthest from the lens center plane in the optical axis direction. The plane passing through a point on the flange surface and orthogonal to the optical axis is defined as the fourth surface, and the plane passing through the center between the third surface and the fourth surface and orthogonal to the optical axis is defined as the flange center surface. The central surface of the lens is biased toward the third surface with respect to the central surface of the flange.
The first flange surface is a flat surface having no recess, and is a flat surface.
The second flange surface has an annular second flange surface side recess centered on the optical axis.
The bottom of the recess on the second flange surface side is arranged on the fourth surface side of the lens center surface.
The second optical surface is a concave surface.
The region of the lens barrel facing the outermost outer peripheral surface of the lens is used as a lens fixing portion, and the lens fixing portion is fitted with a part of the outermost outer peripheral surface of the lens on the fourth surface side. A non-fitting portion in which the lens is press-fitted and intersects the central surface of the lens and a non-fitting portion facing the remaining portion of the outermost peripheral surface of the lens on the third surface side with a gap. It has a door,
The fifth surface is a plane that passes through the bottom of the recess on the second flange surface side and is orthogonal to the optical axis, and the seventh surface is a surface that passes through the boundary between the fitting portion and the non-fitting portion and is orthogonal to the optical axis. The circumference of the outermost peripheral surface between the seventh surface and the fifth surface that divides the outermost surface into two equal parts in the optical axis direction is an optical unit that is substantially on the central surface of the lens . The optical unit according to claim 9 .
The distance between the first surface and the second surface is D1, the distance between the fifth surface and the central surface of the lens is D2, and the distance between the fifth surface and the seventh surface. Is D5, and an optical unit that satisfies the following equation.
| D5 × 0.5-D2 | ≦ D1 × 0.10 The optical unit according to claim 9 or 10.
The second flange surface side recess is an optical unit that is a groove. The optical unit according to any one of claims 9 to 11.
The bottom of the recess on the second flange surface side is an optical unit arranged on the second surface or on the fourth surface side of the second surface. A plurality of optical elements including the lens according to any one of claims 1 to 8 .
The lens barrel containing the optical element and
With
An optical lens in which the lens is press-fitted in a state where the lens fixing portion is fitted with the entire outermost peripheral surface of the lens, with the region of the lens barrel facing the outermost peripheral surface of the lens as the lens fixing portion. unit. The optical unit according to any one of claims 9 to 13 .
The optical element includes a diaphragm
The lens is an optical unit adjacent to the diaphragm. The optical unit for in-vehicle use or monitoring according to any one of claims 9 to 14 .

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