TWI680306B - Imaging lens, imaging device and electronic device having the same - Google Patents

Abstract

An imaging lens group includes an aperture in order from the object side to the image side, a first lens having a negative refractive power, a second lens having a positive refractive power, a third lens having a negative refractive power, and a fourth lens having a positive refractive power. A lens and a fifth lens having a positive refractive power. Among them, the combined focal length of the first lens and the second lens is positive; the image side of the first lens is concave; the object side of the fourth lens is concave and the image side is convex; the object side of the fifth lens is convex. The total number of lenses in this imaging lens group is five. When this imaging lens group meets certain conditions, it can meet the requirements of miniaturization, resistance to environmental changes, and high imaging quality at the same time.

Description

Imaging lens group, imaging device and electronic device

The present invention relates to an imaging lens group and an imaging device, and more particularly to an imaging lens group, an imaging device, and an electronic device that are suitable for use in automotive photography electronic devices or surveillance photography systems.

With the advancement of semiconductor process technology, the pixels of the image sensing element can reach a smaller size, thereby improving the performance of the overall image sensing element. Therefore, the imaging quality of optical imaging lenses must also be continuously improved to meet the needs of today's consumer market.

With the diversified development of consumer electronics products, such as smart phones, sports cameras, driving recorders, reversing photography devices, and home surveillance photography equipment, the design requirements for optical imaging lenses have also become more diverse. Taking car photography devices as an example, optical imaging lenses are generally required to have better environmental adaptability, such as from cold regions with low temperatures to tropical regions with high temperatures, and consistent with temperature changes in different regions and seasons, it is necessary to maintain stable imaging quality. In addition, because consumer electronics products are also designed to be thin, light, and short, related components, including optical imaging lenses, must also be thinner in size. However, it is often difficult to reduce both the viewing angle and the imaging quality of the optical imaging lens.

Therefore, how to provide an optical imaging lens that is miniaturized, resistant to environmental climate change, and has high imaging quality is a goal of continuous efforts of those skilled in the art.

Therefore, in order to solve the above problems, the present invention provides an imaging lens group, which sequentially includes an aperture, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens from the object side to the image side. Among them, the first lens has a negative refractive power, and its image side is concave; the second lens has a positive refractive power; the third lens has a negative refractive power; the fourth lens is a meniscus lens with a positive refractive power, and its object side is The fifth lens has a positive refractive power, and its object side is convex. The total number of lenses of the imaging lens group is five. The effective focal length of the imaging lens group is EFL, the distance from the object side of the first lens to the imaging surface of the imaging lens group on the optical axis is TTL, and the combined focal distance of the first lens and the second lens is f12, which satisfies the following Relations: 0.5 <f12 / EFL <1.6 and 1.8 <TTL / EFL <2.6.

The invention further provides an imaging lens group, which sequentially includes an aperture, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens from the object side to the image side. The first lens has a negative refractive power and its image side is concave. The second lens has a positive refractive power. The combined focal length of the first lens and the second lens is positive. The third lens has a negative refractive power. The four lenses have positive refractive power, and the object side is concave, and the image side is convex; and the fifth lens has positive refractive power, and the object side is convex. The total number of lenses of the imaging lens group is five. The effective focal length of the imaging lens group is EFL, the focal length of the second lens is f2, the distance from the object side of the first lens to the imaging surface of the imaging lens group on the optical axis is TTL, and the maximum image height of the imaging lens group is Is ImgH; the imaging lens group satisfies the following relations: 0.4 <f2 / EFL <0.9; and 3.8 <TTL / ImgH <5.1.

According to an embodiment of the present invention, the imaging lens group satisfies the following relationship: 0.2 <f3 / f1 <0.7; wherein f1 is the focal length of the first lens and f3 is the focal length of the third lens.

According to an embodiment of the present invention, the fourth lens system of the imaging lens group satisfies the following relationship: 0.25 <R8 / R7 <0.6; where R7 is the radius of curvature of the object side of the fourth lens and R8 is the fourth lens image The radius of curvature of the side.

According to an embodiment of the present invention, the imaging lens group satisfies the following relationship: 0.11 <CT4 / TTL <0.19; where CT4 is the thickness of the fourth lens, and TTL is the imaging from the object side of the first lens to the imaging lens group. The distance of a face on the optical axis.

According to an embodiment of the present invention, the fifth lens system of the imaging lens group satisfies the following relationship: 0.7 <(C9 + C10) / (C9-C10) <2.5; wherein the curvature of the object side of the fifth lens is C9 The curvature of the image side is C10.

According to an embodiment of the present invention, the imaging lens group satisfies the following relationship: 0.03 <CT5 / TTL <0.1; wherein CT5 is the thickness of the fifth lens.

According to an embodiment of the present invention, the imaging lens group includes at least two lenses having a refractive index greater than 1.7.

According to an embodiment of the present invention, the second lens of the imaging lens group satisfies the following relationship: Nd2> 1.75; wherein Nd2 is the refractive index of the second lens.

According to an embodiment of the present invention, both the object side and the image side of the third lens of the imaging lens group are aspheric, and the material of the third lens is glass.

According to an embodiment of the present invention, an object side surface of the third lens of the imaging lens group is convex at a near optical axis.

According to an embodiment of the present invention, both the object side and the image side of the second lens of the imaging lens group are convex.

According to an embodiment of the present invention, the imaging lens group satisfies the following relationship: 3.8 <TTL / ImgH <5.1; where TTL is the distance on the optical axis from the side surface of the first lens to the imaging surface of the imaging lens group, ImgH It is the maximum image height of the imaging lens group.

According to an embodiment of the present invention, the imaging lens group satisfies the following relationship: 0.4 <f2 / EFL <0.9; wherein f2 is the focal length of the second lens.

According to an embodiment of the present invention, the imaging lens group satisfies the following relationship: 0.9 <f4 / EFL <1.6; wherein f4 is the focal length of the fourth lens.

According to an embodiment of the present invention, the imaging lens group satisfies the following relationship: 1.3 <f5 / EFL <6; wherein f5 is the focal length of the fifth lens.

According to an embodiment of the present invention, the imaging lens group satisfies the following relationship: 0.7 <AT34 / (AT12 + AT23 + AT45) <4.3; where AT12 is the image side of the first lens to the object side of the second lens on the optical axis AT23 is the distance on the optical axis from the second lens image side to the third lens object side, AT34 is the distance on the optical axis from the third lens image side to the fourth lens object side, and AT45 is the fourth lens image. The distance from the side surface to the object side surface of the fifth lens on the optical axis.

The present invention further provides an imaging device. The imaging device includes the aforementioned imaging lens group and an image sensing element.

The invention further provides an electronic device. The electronic device includes the imaging device as described above and a near-infrared emitting element.

In order to make the above features and advantages of the present invention more comprehensible, a few embodiments are listed below and described in detail with reference to the accompanying drawings.

10, 20, 30, 40, 50, 60, 70, 80, 90‧‧‧ imaging lens groups

11, 21, 31, 41, 51, 61, 71, 81, 91‧‧‧ first lens

12, 22, 32, 42, 52, 62, 72, 82, 92‧‧‧Second lens

13, 23, 33, 43, 53, 63, 73, 83, 93‧‧‧ third lens

14, 24, 34, 44, 54, 64, 74, 84, 94‧‧‧ fourth lens

15, 25, 35, 45, 55, 65, 75, 85, 95‧‧‧ fifth lens

16, 26, 36, 46, 56, 66, 76, 86, 96‧‧‧ filter elements

17, 27, 37, 47, 57, 67, 77, 87, 97‧‧‧ protection glass

18, 28, 38, 48, 58, 68, 78, 88, 98‧‧‧ imaging surfaces

11a, 21a, 31a, 41a, 51a, 61a, 71a, 81a, 91a ‧‧‧ side of the first lens

11b, 21b, 31b, 41b, 51b, 61b, 71b, 81b, 91b ‧‧‧ side of the image of the first lens

12a, 22a, 32a, 42a, 52a, 62a, 72a, 82a, 92a ‧‧‧ side of the second lens

12b, 22b, 32b, 42b, 52b, 62b, 72b, 82b, 92b ‧‧‧ side of the second lens

13a, 23a, 33a, 43a, 53a, 63a, 73a, 83a, 93a ‧‧‧ side of the third lens

13b, 23b, 33b, 43b, 53b, 63b, 73b, 83b, 93b ‧‧‧ side of the image of the third lens

14a, 24a, 34a, 44a, 54a, 64a, 74a, 84a, 94a ‧‧‧ object side of the fourth lens

14b, 24b, 34b, 44b, 54b, 64b, 74b, 84b, 94b ‧‧‧ the side of the image of the fourth lens

15a, 25a, 35a, 45a, 55a, 65a, 75a, 85a, 95a ‧‧‧ Fifth lens object side

15b, 25b, 35b, 45b, 55b, 65b, 75b, 85b, 95b ‧‧‧ Fifth lens image side

16a, 16b, 26a, 26b, 36a, 36b, 46a, 46b, 56a, 56b, 66a, 66b, 76a, 76b, 86a, 86b, 96a, 96b.

17a, 17b, 27a, 27b, 37a, 37b, 47a, 47b, 57a, 57b, 67a, 67b, 77a, 77b, 87a, 87b, 97a, 97b ‧ ‧ two surfaces of protective glass

100, 200, 300, 400, 500, 600, 700, 800, 900‧‧‧ image sensor

1000‧‧‧ electronic device

1010‧‧‧ Imaging Device

1020‧‧‧Near-infrared emitting element

I‧‧‧ Optical axis

ST‧‧‧ aperture

[Fig. 1A] is a schematic diagram of an imaging lens group according to the first embodiment of the present invention; [Fig. 1B] is a longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration of the first embodiment of the present invention in order from left to right. [Fig. 2A] is a schematic diagram of an imaging lens group according to a second embodiment of the present invention; [Fig. 2B] From left to right, the longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram of the second embodiment of the present invention; [Fig. 3A] is the imaging lens group of the third embodiment of the present invention. Schematic diagram; [Fig. 3B] From left to right, the longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram of the third embodiment of the present invention; [Fig. 4A] is the imaging of the fourth embodiment of the present invention. Schematic diagram of the lens group; [Fig. 4B] From left to right, the longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram of the fourth embodiment of the invention; [Fig. 5A] of the fifth embodiment of the invention Schematic diagram of the imaging lens group; [Fig. 5B] From left to right, the longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram of the fifth embodiment of the present invention; [Fig. 6A] is the sixth of the present invention. Schematic diagram of the imaging lens group of the embodiment; [Fig. 6B] From left to right, the longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram of the sixth embodiment of the invention; [Fig. 7A] is the invention Schematic diagram of the imaging lens group of the seventh embodiment; [FIG. 7B] The longitudinal direction of the seventh embodiment of the present invention from left to right Spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram; [Fig. 8A] is a schematic diagram of an imaging lens group according to an eighth embodiment of the present invention; [Fig. 8B] is an eighth embodiment of the present invention in order from left to right. Longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram; [Fig. 9A] is a schematic diagram of an imaging lens group according to a ninth embodiment of the present invention; [Fig. 9B] is the ninth of the present invention in order from left to right. Longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram of the embodiment; and 10 is a schematic diagram of an electronic device according to an eleventh embodiment of the present invention.

In the following embodiments, each lens of the imaging lens group may be made of glass or plastic, and is not limited to the materials listed in the embodiments. When the lens material is glass, the lens surface can be processed by grinding or molding. In addition, because the glass material itself is resistant to temperature changes and high hardness, it can reduce the impact of environmental changes on the imaging lens group, thereby extending the imaging lens group. Life. When the lens material is plastic, it is beneficial to reduce the weight of the imaging lens group and reduce the production cost.

In the embodiment of the present invention, each lens includes an object side facing an object and an image side facing an imaging surface. The surface shape of each lens is defined according to the shape of the surface near the optical axis region (at the paraxial axis). For example, when describing the object side of a lens as convex, it means that the lens is convex on the object side near the optical axis region. That is, although the lens surface is described as being convex in the embodiment, the surface may be convex or concave in a region (off-axis) away from the optical axis. The shape at the paraxial of each lens is judged by the positive or negative curvature radius of the surface. For example, if the curvature radius of the object side of a lens is positive, the side of the object is convex; otherwise, if its If the radius of curvature is negative, the side of the object is concave. For the image side of a lens, if its curvature radius is positive, the image side is concave; otherwise, if its curvature radius is negative, the image side is convex.

In the embodiment of the present invention, the total track length (TTL) of the imaging lens group is defined as the distance from the object side to the imaging surface of the first lens of the imaging lens group on the optical axis. The imaging height of this imaging lens group is called the maximum image height ImgH (Image Height); when an image sensing element is set on the imaging surface, the maximum image height ImgH represents half of the diagonal length of the effective sensing area of the image sensing element . In the following examples, the curvature radius, lens thickness, distance between lenses, The units of total lens length TTL, maximum image height ImgH, and focal length (Focal Length) are all expressed in millimeters (mm).

The invention provides an imaging lens group, which sequentially includes an aperture, a first lens, a second lens, a third lens, a fourth lens, and a fifth lens from the object side to the image side. The total number of lenses in this imaging lens group is five.

The first lens has a negative refractive power, and its image side is concave. Thereby, the light receiving range can be increased and the shooting angle of the imaging lens group can be enlarged.

The second lens has a positive refractive power for condensing light. The combined focal length of the first lens and the second lens is a positive value. Therefore, by providing the first lens and the second lens, it is possible to receive incident light at a larger angle and effectively correct aberrations.

The third lens has a negative refractive power and is used as an element for adjusting the light path to guide light to the fourth and fifth lenses at the rear to increase the image height of the imaging lens group on the imaging surface. By providing a third lens having a negative refractive power, the distortion aberration of the imaging lens group can be effectively corrected.

The fourth lens has a positive refractive power. The fourth lens is a meniscus lens, and the object side is concave and the image side is convex.

The fifth lens has a positive refractive power, and its object side is convex. With the configuration of the refractive power of the fourth lens and the fifth lens, and the structure in which the convex sides of the image side of the fourth lens and the object side of the fifth lens are opposite, the field curvature aberration and spherical image of the imaging lens group can be effectively corrected. difference.

The effective focal length of the imaging lens group is EFL, and the combined focal length of the first lens and the second lens is f12. This imaging lens group satisfies the following relationship: 0.5 <f12 / EFL <1.6 (1); and 1.8 <TTL / EFL <2.6 (2); By satisfying the conditions of the relational expressions (1) and (2), it is advantageous to reduce the volume of the imaging lens group while maintaining good optical performance. If f12 / EFL exceeds the upper limit of relationship (1), it will be difficult to correct spherical aberration and comet aberration; if f12 / EFL is lower than the lower limit of relationship (1), the total length of the imaging lens group will be longer. .

The focal length of the third lens of the imaging lens group is f3, and the focal length f1 of the first lens satisfies the following relationship: 0.2 <f3 / f1 <0.7; (3); by satisfying the relationship (3) Conditions are conducive to correcting distortion aberrations of the imaging lens group.

The distance between the imaging lens group from the object side of the first lens to the imaging surface on the optical axis is TTL, and one and a half of the diagonal of the effective sensing area of the image sensing element on the imaging surface is ImgH. The following relational expression: 3.8 <TTL / ImgH <5.1 (4); By satisfying the condition of the relational expression (4), it is beneficial to maintain the miniaturization of the imaging lens group.

The focal length of the second lens of the imaging lens group is f2, which satisfies the following relationship between the effective focal length EFL of the imaging lens group: 0.4 <f2 / EFL <0.9; (5); by satisfying the relationship (5) Conditions, the angle of incident light on the surface of the third lens can be reduced by the positive refractive power provided by the second lens, which is beneficial to correct the aberration of the imaging lens group.

The fourth lens of the imaging lens group satisfies the following relationship: 0.25 <R8 / R7 <0.6 (6); wherein R7 is the curvature radius of the object side of the fourth lens, and R8 is the curvature radius of the image side of the fourth lens. By satisfying the condition of the relational expression (6), it is beneficial to correct the field curvature aberration of the imaging lens group.

The fourth lens further satisfies the following relationship: 0.11 <CT4 / TTL <0.19 (7); where CT4 is the thickness of the fourth lens.

The curvature of the object side of the fifth lens of the imaging lens group is C9, and the curvature of the image side is C10, which satisfies the following relationship: 0.7 <(C9 + C10) / (C9-C10) <2.5 (8); Satisfying the condition of the relational expression (8) is favorable for correcting the spherical aberration of the imaging lens group.

The fifth lens further satisfies the following relationship: 0.03 <CT5 / TTL <0.1 (9); where CT5 is the thickness of the fifth lens on the optical axis.

The imaging lens group has five lenses with refractive power, including at least two lenses having a refractive index greater than 1.7. Thereby, the imaging aberration of the imaging lens group can be reduced.

The imaging lens group further satisfies the following relationship: Nd2> 1.75 (10); wherein Nd2 is the refractive index of the second lens. By satisfying the condition of the relational expression (10), it is advantageous to reduce the distortion aberration of the imaging lens group.

Both the object side and the image side of the third lens of the imaging lens group are aspheric, and the material of the third lens is glass.

The focal length of the fourth lens of the imaging lens group is f4, and the effective focal length EFL of the imaging lens group satisfies the following relationship: 0.9 <f4 / EFL <1.6 (11).

The focal length of the fifth lens of the imaging lens group is f5, and the effective focal length EFL of the imaging lens group satisfies the following relationship: 1.3 <f5 / EFL <6 (12).

The distance between the first lens image side to the second lens object side on the optical axis of the imaging lens group is AT12, the distance between the second lens image side to the third lens object side on the optical axis is AT23, and the third lens image The distance from the side to the object side of the fourth lens on the optical axis is AT34. The distance from the side of the fourth lens image to the side of the fifth lens on the optical axis is AT45, which satisfies the following relationship: 0.7 <AT34 / (AT12 + AT23 + AT45) <4.3 (13); By satisfying the condition of the relational expression (13), it is beneficial to control the total length of the imaging lens group and to correct aberrations.

First embodiment

1A and 1B, FIG. 1A is a schematic diagram of an imaging lens group according to a first embodiment of the present invention. FIG. 1B is a longitudinal spherical aberration diagram (Astigmatism / Field Curvature) and a distortion aberration diagram (Distortion) of the first embodiment of the present invention in order from left to right.

As shown in FIG. 1A, the imaging lens group 10 of the first embodiment sequentially includes an aperture ST, a first lens 11, a second lens 12, a third lens 13, a fourth lens 14, and a fifth lens from the object side to the image side. 15. The imaging lens group 10 further includes a filter element 16, a protective glass 17, and an imaging surface 18. An image sensing element 100 may be further disposed on the imaging surface 18 to constitute an imaging device (not otherwise labeled).

The first lens 11 has a negative refractive power, the object side surface 11a is a flat surface, the image side surface 11b is a concave surface, and both the object side surface 11a and the image side surface 11b are spherical surfaces. The material of the first lens 11 is glass.

The second lens 12 has a positive refractive power, and its object-side surface 12a is convex, and its image-side 12b is convex, and its object-side 12a and image-side 12b are spherical. The material of the second lens 12 is glass. The composite focal length of the first lens 11 and the second lens 12 is a positive value.

The third lens 13 has a negative refractive power, and its object side surface 13a is convex (convex at the paraxial axis and concave at off axis), its image side 13b is concave, and both the object side 13a and the image side 13b are aspheric. The third lens is made of glass.

The fourth lens 14 is a meniscus lens having a positive refractive power. The object side surface 14a is a concave surface, the image side surface 14b is a convex surface, and the object side surface 14a and the image side surface 14b are spherical surfaces. The material of the fourth lens is glass.

The fifth lens 15 has a positive refractive power, the object side surface 15a is a convex surface, the image side surface 15b is a concave surface, and the object side surface 15a and the image side surface 15b are both spherical surfaces. The fifth lens is made of glass.

The filter element 16 is disposed between the fifth lens 15 and the imaging surface 18, and is configured to filter out light in a specific wavelength range. The two surfaces 16a, 16b of the filter element 16 are both flat, and the material is glass.

The protective glass 17 is disposed on the image sensing element 100. The two surfaces 17a, 17b are both flat, and the material is glass.

The image sensor 100 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor sensor (CMOS Image Sensor).

The curve equations of the above aspheric surfaces are expressed as follows:

Among them, X: the distance between the point on the aspheric surface where the optical axis is Y and the tangent plane of the aspheric surface on the optical axis; Y: the vertical distance between the point on the aspheric surface and the optical axis; R: the lens is near the optical axis Radius of curvature; K: cone coefficient; and Ai: aspherical coefficient of order i.

Please refer to Table 1 below for detailed optical data of the imaging lens group 10 according to the first embodiment of the present invention. Among them, the object side surface 11a of the first lens 11 is designated as the surface 11a, the image side surface 11b is designated as the surface 11b, and the other lens surfaces are deduced by analogy. The value in the distance column in the table represents the distance from the surface to the next surface on the optical axis I. For example, the distance from the object side 11a to the image side 11b of the first lens 11 is 0.5 mm, which represents that the first lens 11 is on the optical axis The thickness is 0.5mm. The distance from the image side 11b of the first lens 11 to the object side 12a of the second lens 12 is 0.08 mm. Others can be deduced by analogy, which will not be repeated below.

In the first embodiment, the effective focal length of the imaging lens group 10 is EFL, the aperture value (F-number) is Fno, one and a half of the maximum viewing angle of the overall imaging lens group 10 is HFOV (Half Field of View), the object of the first lens 11 The distance from the side surface 11a to the imaging surface 18 on the optical axis I is the total length TTL. On the imaging surface 18, one half of the diagonal of the effective sensing area of the image sensing element 100 is the maximum image height ImgH, and the value is as follows: EFL = 5.63mm , Fno = 2.10, TTL = 12.22mm, HFOV = 30.5 degrees, ImgH = 3.14mm.

Please refer to Table 2 below, which shows aspheric coefficients of the surfaces of the third lens 13 according to the first embodiment of the present invention. Among them, K is the cone coefficient in the aspheric curve equation, and A ₄ to A ₁₀ represent the aspheric coefficients of the 4th to 10th order of each surface. For example, the taper coefficient K of the object side 13a of the third lens 13 is -1210. Others can be deduced by analogy, which will not be repeated below. In addition, the tables of the following embodiments correspond to the imaging lens groups of the embodiments, and the definitions of the tables are the same as those of this embodiment, so they will not be repeated in the following embodiments.

In the first embodiment, the relationship between the combined focal length f12 of the first lens 11 and the second lens 12 and the effective focal length EFL of the imaging lens group 10 is f12 / EFL = 1.112.

In the first embodiment, the distance on the optical axis from the object side 11a of the first lens 11 to the imaging surface of the imaging lens group 10 is TTL, and the relationship between the distance from the object lens 11 and the effective focal length EFL of the imaging lens group 10 is TTL / EFL = 2.170.

In the first embodiment, the relationship between the focal length f1 of the first lens 11 and the focal length f3 of the third lens 13 is f3 / f1 = 0.476.

In the first embodiment, the relationship between the TTL of the imaging lens group 10 and the maximum image height ImgH is TTL / ImgH = 3.897.

In the first embodiment, the relationship between the focal length f2 of the second lens and the effective focal length EFL of the imaging lens group 10 is f2 / EFL = 0.745.

In the first embodiment, the relationship between the curvature radius R7 of the object side surface 14a of the fourth lens 14 and the curvature radius R8 of the image side surface 14b is R8 / R7 = 0.407.

In the first embodiment, the relationship between the thickness CT4 of the fourth lens 14 on the optical axis and the total length TTL of the imaging lens group 10 is CT4 / TTL = 0.156.

In the first embodiment, the relationship between the curvature C9 of the object side surface 15 a and the curvature C10 of the image side surface of the fifth lens 15 is (C9 + C10) / (C9-C10) = 1.163.

In the first embodiment, the relationship between the thickness CT5 of the fifth lens 15 on the optical axis and the total length TTL of the imaging lens group 10 is CT5 / TTL = 0.078.

In the first embodiment, the refractive index Nd2 of the second lens 12 is 1.834.

In the first embodiment, the relationship between the focal length f4 of the fourth lens 14 and the effective focal length EFL of the imaging lens group 10 is f4 / EFL = 1.214.

In the first embodiment, the relationship between the focal length f5 of the fifth lens 15 and the effective focal length EFL of the imaging lens group 10 is f5 / EFL = 3.162.

In the first embodiment, the distance AT12 on the optical axis between the image side 11b of the first lens 11 to the object side 12a of the second lens 12 and the distance on the optical axis of the image side 12b of the second lens 12 to the object side 13a of the third lens 13 AT23, distance AT34 on the optical axis between the image side 13b of the third lens 13 to the object side 14a of the fourth lens 14 and distance AT45 on the optical axis from the image side 14b of the third lens 14 to the object side 15a of the fifth lens 15 The relationship is AT34 / (AT12 + AT23 + AT45) = 4.076.

It can be seen from the numerical values of the above-mentioned relational expressions that the imaging lens group 10 of the first embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 1B, from left to right, the longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram of the imaging lens group 10 are shown. From the longitudinal spherical aberration diagram, it can be seen that three types of off-axis rays with wavelengths of 900nm, 940nm, and 980nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.05mm. From the astigmatic field curvature aberration diagram (wavelength 940nm), it can be seen that the change in the focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.08mm; the focal length of the aberration in the meridional direction is within the entire field of view The variation is within ± 0.04mm; and the distortion aberration can be controlled within 6%. As shown in FIG. 1B, the imaging lens group 10 of this embodiment has well corrected various aberrations, which meets the imaging quality requirements of the optical system.

Second embodiment

2A and 2B, FIG. 2A is a schematic diagram of an imaging lens group 20 according to a second embodiment of the present invention. 2B is a longitudinal spherical aberration diagram (Astigmatism / Field Curvature) and a distortion aberration diagram (Distortion) of the second embodiment of the present invention in order from left to right.

As shown in FIG. 2A, the imaging lens group 20 of the second embodiment sequentially includes an aperture ST, a first lens 21, a second lens 22, a third lens 23, a fourth lens 24, and a fifth lens from the object side to the image side. 25. The imaging lens group 20 may further include a filter element 26, a protective glass 27, and an imaging surface 28. An image sensing element 200 may be further disposed on the imaging surface 28 to constitute an imaging device (not otherwise labeled).

The first lens 21 has a negative refractive power, the object side surface 21a is a convex surface, the image side surface 21b is a concave surface, and both the object side surface 21a and the image side surface 21b are spherical surfaces. The material of the first lens 21 is glass.

The second lens 22 has a positive refractive power, and its object-side surface 22a is convex, and its image-side 22b is convex, and its object-side 22a and image-side 22b are spherical. The material of the second lens 22 is glass.

The third lens 23 has a negative refractive power, and its object side 23a is convex (convex at the paraxial and concave at the off-axis), its image side 23b is concave, and its object side 23a and image side 23b are aspheric. . The material of the third lens 23 is glass.

The fourth lens 24 has a positive refractive power, the object side surface 24a is a concave surface, the image side surface 24b is a convex surface, and the object side surface 24a and the image side surface 24b are both spherical surfaces. The material of the fourth lens 24 is glass.

The fifth lens 25 has a positive refractive power, and its object-side surface 25a is convex, and its image-side 25b is convex, and its object-side 25a and image-side 25b are spherical. The material of the fifth lens 25 is glass.

The filter element 26 is disposed between the fifth lens 25 and the imaging surface 28 and is configured to filter out light in a specific wavelength range. The two surfaces 26a, 26b of the filter element 26 are both flat, and the material is glass.

The protective glass 27 is disposed on the image sensing element 200. The two surfaces 27 a and 27 b are both flat and the material is glass.

The image sensor 200 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor).

The detailed optical data of the imaging lens group 20 and the aspheric coefficient of the lens surface of the second embodiment are listed in Tables 3 and 4, respectively. In the second embodiment, the curve equation of the aspherical surface is expressed as the first embodiment.

In the second embodiment, the values of the relational expressions of the imaging lens group 20 are listed in Table 5. As can be seen from Table 5, the imaging lens group 20 of the second embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 2B, from left to right in the figure are longitudinal spherical aberration diagrams, astigmatic field curvature aberration diagrams, and distortion aberration diagrams of the imaging lens group 20, respectively. From the longitudinal spherical aberration diagram, it can be seen that three types of off-axis rays with wavelengths of 900nm, 940nm, and 980nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.05mm. From the astigmatic field curvature aberration diagram (wavelength 940nm), it can be seen that the change in the focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.08mm; the focal length of the aberration in the meridional direction is within the entire field of view The variation is within ± 0.05mm; the distortion aberration can be controlled within 7%. As shown in FIG. 2B, the imaging lens group 20 of this embodiment has well corrected various aberrations, and meets the imaging quality requirements of the optical system.

Third embodiment

3A and 3B, FIG. 3A is a schematic diagram of an imaging lens group 30 according to a third embodiment of the present invention. FIG. 3B is a longitudinal spherical aberration diagram of the third embodiment of the present invention in sequence from left to right. Spherical Aberration), Astigmatism / Field Curvature, and Distortion.

As shown in FIG. 3A, the imaging lens group 30 of the third embodiment sequentially includes an aperture ST, a first lens 31, a second lens 32, a third lens 33, a fourth lens 34, and a fifth lens from the object side to the image side. 35. The imaging lens group 30 may further include a filter element 36, a protective glass 37, and an imaging surface 38. An image sensing element 300 may be further disposed on the imaging surface 38 to constitute an imaging device (not otherwise labeled).

The first lens 31 has a negative refractive power, the object side surface 31a is a convex surface, the image side surface 31b is a concave surface, and both the object side surface 31a and the image side surface 31b are spherical surfaces. The material of the first lens 31 is glass.

The second lens 32 has a positive refractive power, the object side surface 32a is a convex surface, the image side surface 32b is a convex surface, and both the object side surface 32a and the image side surface 32b are spherical surfaces. The material of the second lens 32 is glass.

The third lens 33 has a negative refractive power, and its object side 33a is convex (convex at the paraxial axis and concave at the off axis), its image side 33b is concave, and its object side 33a and image side 33b are aspheric. . The material of the third lens 33 is glass.

The fourth lens 34 has a positive refractive power, the object side surface 34a is a concave surface, the image side surface 34b is a convex surface, and both the object side surface 34a and the image side surface 34b are spherical surfaces. The material of the fourth lens 34 is glass.

The fifth lens 35 has a positive refractive power, the object side surface 35a is a convex surface, the image side surface 35b is a concave surface, and the object side surface 35a and the image side surface 35b are both spherical surfaces. The material of the fifth lens 35 is glass.

The filter element 36 is disposed between the fifth lens 35 and the imaging surface 38 and is configured to filter out light in a specific wavelength range. The two surfaces 36a, 36b of the filter element 36 are both flat, and the material is glass.

The protective glass 37 is disposed on the image sensing element 300. The two surfaces 37 a and 37 b are both flat and the material is glass.

The image sensor 300 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor).

The detailed optical data of the imaging lens group 30 and the aspheric coefficient of the lens surface of the third embodiment are listed in Table 6 and Table 7, respectively. In the third embodiment, the curve equation of the aspherical surface is expressed as the first embodiment.

Table seven

In the third embodiment, the values of the relational expressions of the imaging lens group 30 are listed in Table 8. As can be seen from Table 8, the imaging lens group 30 of the third embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 3B, from left to right in the figure are longitudinal spherical aberration diagrams, astigmatic field curvature aberration diagrams, and distortion aberration diagrams of the imaging lens group 30, respectively. From the longitudinal spherical aberration diagram, it can be seen that three types of off-axis rays with wavelengths of 900nm, 940nm, and 980nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.05mm. From the astigmatic field curvature aberration diagram (wavelength 940nm), it can be seen that the change in focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.06mm; the focal length of the aberration in the meridional direction is within the entire field of view. The variation is within ± 0.05mm; the distortion aberration can be controlled within 7%. As shown in FIG. 3B, the imaging lens group 30 of this embodiment has well corrected various aberrations, which meets the imaging quality requirements of the optical system.

Fourth embodiment

4A and 4B, FIG. 4A is a schematic diagram of an imaging lens group 40 according to a fourth embodiment of the present invention. FIG. 4B is a longitudinal spherical aberration diagram of the fourth embodiment of the present invention in sequence from left to right. Spherical Aberration), Astigmatism / Field Curvature, and Distortion.

As shown in FIG. 4A, the imaging lens group 40 of the fourth embodiment sequentially includes an aperture ST, a first lens 41, a second lens 42, a third lens 43, a fourth lens 44, and a fifth lens from the object side to the image side. 45. The imaging lens group 40 may further include a filter element 46, a protective glass 47 and an imaging surface 48. An image sensing element 400 may be further disposed on the imaging surface 48 to constitute an imaging device (not otherwise labeled).

The first lens 41 has a negative refractive power, the object side surface 41a is a flat surface, the image side surface 41b is a concave surface, and both the object side surface 41a and the image side surface 41b are spherical surfaces. The material of the first lens 41 is glass.

The second lens 42 has a positive refractive power, the object side surface 42a is a convex surface, the image side surface 42b is a convex surface, and both the object side surface 42a and the image side surface 42b are spherical surfaces. The material of the second lens 42 is glass.

The third lens 43 has a negative refractive power, and its object-side surface 43a is convex (convex at the paraxial and concave at the off-axis), its image-side 43b is concave, and its object-side 43a and image-side 43b are aspheric. . The material of the third lens 43 is glass.

The fourth lens 44 has a positive refractive power, the object side surface 44a is a concave surface, the image side surface 44b is a convex surface, and the object side surface 44a and the image side surface 44b are both spherical surfaces. The material of the fourth lens 44 is glass.

The fifth lens 45 has a positive refractive power, the object side surface 45a is a convex surface, the image side surface 45b is a concave surface, and the object side surface 45a and the image side surface 45b are both spherical surfaces. The fifth lens 45 is made of glass.

The filter element 46 is disposed between the fifth lens 45 and the imaging surface 48 and is configured to filter out light in a specific wavelength range. The two surfaces 46a, 46b of the filter element 46 are both flat, and the material is glass.

The protective glass 47 is disposed on the image sensing element 400. The two surfaces 47a and 47b are both flat and the material is glass.

The image sensor 400 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor).

The detailed optical data of the imaging lens group 40 and the aspheric coefficient of the lens surface of the fourth embodiment are listed in Tables 9 and 10, respectively. In the fourth embodiment, the curve equation of the aspherical surface is expressed as the first embodiment.

Table ten

In the fourth embodiment, the values of the relational expressions of the imaging lens group 40 are listed in Table 11. As can be seen from Table 11, the imaging lens group 40 of the fourth embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 4B, from left to right, the longitudinal spherical aberration diagram, astigmatic field curvature aberration diagram, and distortion aberration diagram of the imaging lens group 40 are shown. From the longitudinal spherical aberration diagram, it can be seen that three types of off-axis rays with wavelengths of 900nm, 940nm, and 980nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.05mm. From the astigmatic field curvature aberration diagram (wavelength 940nm), it can be seen that the change in focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.05mm; the focal length of the aberration in the meridional direction is within the entire field of view The variation is within ± 0.09mm; the distortion aberration can be controlled within 6%. As shown in FIG. 4B, the imaging lens group 40 of this embodiment has well corrected various aberrations, which meets the imaging quality requirements of the optical system.

Fifth Embodiment

5A and 5B, FIG. 5A is a schematic diagram of an imaging lens group 50 according to a fifth embodiment of the present invention. FIG. 5B is a longitudinal spherical aberration diagram of the fifth embodiment of the present invention in sequence from left to right. Spherical Aberration), Astigmatism / Field Curvature, and Distortion.

As shown in FIG. 5A, the imaging lens group 50 of the fifth embodiment sequentially includes an aperture ST, a first lens 51, a second lens 52, a third lens 53, a fourth lens 54, and a fifth lens from the object side to the image side. 55. The imaging lens group 50 may further include a filter element 56, a protective glass 57, and an imaging surface 58. An image sensing element 500 may be further disposed on the imaging surface 58 to constitute an imaging device (not otherwise labeled).

The first lens 51 has a negative refractive power, the object side surface 51a is a concave surface, the image side surface 51b is a concave surface, and both the object side surface 51a and the image side surface 51b are spherical surfaces. The material of the first lens 51 is glass.

The second lens 52 has a positive refractive power, the object side surface 52a is a convex surface, the image side surface 52b is a convex surface, and the object side surface 52a and the image side surface 52b are both spherical surfaces. The material of the second lens 52 is glass.

The third lens 53 has a negative refractive power, and its object-side surface 53a is convex (convex at the paraxial and concave at the off-axis), its image-side 53b is concave, and its object-side 53a and image-side 53b are aspheric. . The material of the third lens 53 is glass.

The fourth lens 54 has a positive refractive power, the object side surface 54a is a concave surface, the image side surface 54b is a convex surface, and the object side surface 54a and the image side surface 54b are both spherical surfaces. The material of the fourth lens 54 is glass.

The fifth lens 55 has a positive refractive power, the object side surface 55a is a convex surface, the image side surface 55b is a convex surface, and the object side surface 55a and the image side surface 55b are both spherical surfaces. The fifth lens 55 is made of glass.

The filter element 56 is disposed between the fifth lens 55 and the imaging surface 58 and is configured to filter out light in a specific wavelength range. The two surfaces 56a, 56b of the filter element 56 are both flat, and the material is glass.

The protective glass 57 is disposed on the image sensing element 500. The two surfaces 57a and 57b are both flat and the material is glass.

The image sensor 500 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor).

The detailed optical data of the imaging lens group 50 and the aspheric coefficient of the lens surface of the fifth embodiment are listed in Tables 12 and 13, respectively. In the fifth embodiment, the curve equation of the aspherical surface is expressed as the first embodiment.

Table 13

In the fifth embodiment, the numerical values of the relational expressions of the imaging lens group 50 are listed in Table XIV. As can be seen from Table 14, the imaging lens group 50 of the fifth embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 5B, from left to right in the figure are longitudinal spherical aberration diagrams, astigmatic field curvature aberration diagrams, and distortion aberration diagrams of the imaging lens group 50, respectively. From the longitudinal spherical aberration diagram, it can be seen that three types of off-axis rays with wavelengths of 900nm, 940nm, and 980nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.05mm. From the astigmatic field curvature aberration diagram (wavelength 940nm), it can be seen that the change in focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.06mm; the focal length of the aberration in the meridional direction is within the entire field of view. The amount of change is within ± 0.06mm; and the distortion aberration can be controlled within 9%. As shown in FIG. 5B, the imaging lens group 50 of this embodiment has well corrected various aberrations, which meets the imaging quality requirements of the optical system.

Sixth embodiment

6A and 6B, FIG. 6A is a schematic diagram of an imaging lens group 60 according to a sixth embodiment of the present invention. FIG. 6B is a longitudinal spherical aberration diagram of the sixth embodiment of the present invention in sequence from left to right. Spherical Aberration), Astigmatism / Field Curvature, and Distortion.

As shown in FIG. 6A, the imaging lens group 60 of the sixth embodiment sequentially includes an aperture ST, a first lens 61, a second lens 62, a third lens 63, a fourth lens 64, and a fifth lens from the object side to the image side. 65. The imaging lens group 60 may further include a filter element 66, a protective glass 67 and an imaging surface 68. An image sensing element 600 may be further disposed on the imaging surface 68 to constitute an imaging device (not otherwise labeled).

The first lens 61 has a negative refractive power, the object side surface 61a is a flat surface, the image side surface 61b is a concave surface, and both the object side surface 61a and the image side surface 61b are spherical surfaces. The material of the first lens 61 is glass.

The second lens 62 has a positive refractive power, its object side surface 62a is convex, and its image side 62b is convex, and its object side 62a and image side 62b are spherical. The material of the second lens 62 is glass.

The third lens 63 has a negative refractive power, and its object-side surface 63a is concave, its image-side 63b is concave, and both its object-side 63a and image-side 63b are aspheric. The material of the third lens 63 is glass.

The fourth lens 64 has a positive refractive power, the object side surface 64a is a concave surface, the image side surface 64b is a convex surface, and the object side surface 64a and the image side surface 64b are both spherical surfaces. The material of the fourth lens 64 is glass.

The fifth lens 65 has a positive refractive power, the object side surface 65a is a convex surface, the image side surface 65b is a concave surface, and the object side surface 65a and the image side surface 65b are both spherical surfaces. The fifth lens 65 is made of glass.

The filter element 66 is disposed between the fifth lens 65 and the imaging surface 68 and is configured to filter out light in a specific wavelength range. The two surfaces 66a, 66b of the filter element 66 are both flat, and the material is glass.

The protective glass 67 is disposed on the image sensing element 600. The two surfaces 67a, 67b are both flat, and the material is glass.

The image sensor 600 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor).

The detailed optical data of the imaging lens group 60 and the aspheric coefficient of the lens surface of the sixth embodiment are listed in Table 15 and Table 16, respectively. In the sixth embodiment, the curve equation of the aspherical surface is expressed as the first embodiment.

In the sixth embodiment, the numerical values of the relational expressions of the imaging lens group 60 are listed in Table 17. As can be seen from Table 17, the imaging lens group 60 of the sixth embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 6B, from left to right in the figure are longitudinal spherical aberration diagrams, astigmatic field curvature aberration diagrams, and distortion aberration diagrams of the imaging lens group 60, respectively. From the longitudinal spherical aberration diagram, it can be seen that the three types of near-infrared rays at 900nm, 940nm, and 980nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.1mm. From the astigmatic field curvature aberration diagram (wavelength 940nm), it can be seen that the change in the focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.08mm; the focal length of the aberration in the meridional direction is within the entire field of view. The amount of change is within ± 0.1mm; and the distortion aberration can be controlled within 5%. As shown in FIG. 6B, the imaging lens group 60 of this embodiment has well corrected various aberrations, which meets the imaging quality requirements of the optical system.

Seventh embodiment

7A and 7B, FIG. 7A is a schematic diagram of an imaging lens group 70 according to a seventh embodiment of the present invention. FIG. 7B is a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration), an astigmatism field curvature aberration diagram (Astigmatism / Field Curvature), and a distortion aberration diagram (Distortion) of the seventh embodiment of the present invention in order from left to right.

As shown in FIG. 7A, the imaging lens group 70 of the seventh embodiment includes an aperture ST, a first lens 71, a second lens 72, a third lens 73, a fourth lens 74, and a fifth lens in this order from the object side to the image side. 75. The imaging lens group 70 may further include a filter element 76, a protective glass 77, and an imaging surface 78. An image sensing element 700 may be further disposed on the imaging surface 78 to constitute an imaging device (not otherwise labeled).

The first lens 71 has a negative refractive power, an object side surface 71a thereof is convex, an image side surface 71b is concave, and both the object side surface 71a and the image side surface 71b are spherical surfaces. The material of the first lens 71 is glass.

The second lens 72 has a positive refractive power, and its object-side surface 72a is convex, and its image-side 72b is convex, and its object-side 72a and image-side 72b are spherical. The material of the second lens 72 is glass.

The third lens 73 has a negative refractive power, and its object side surface 73a is a concave surface, its image side surface 73b is a concave surface, and its object side surface 73a and its image side surface 73b are spherical surfaces. The material of the third lens 73 is glass.

The fourth lens 74 has a positive refractive power, the object side surface 74a is a concave surface, the image side surface 74b is a convex surface, and both the object side surface 74a and the image side surface 74b are spherical surfaces. The material of the fourth lens 74 is glass.

The fifth lens 75 has a positive refractive power, the object side surface 75a is a convex surface, the image side surface 75b is a concave surface, and the object side surface 75a and the image side surface 75b are both spherical surfaces. The material of the fifth lens 75 is glass.

The filter element 76 is disposed between the fifth lens 75 and the imaging surface 78 and is configured to filter out light in a specific wavelength range. The two surfaces 76a, 76b of the filter element 76 are both flat, and the material is glass.

The protective glass 77 is disposed on the image sensing element 700. The two surfaces 77a and 77b are both flat and the material is glass.

The image sensor 700 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor).

The detailed optical data of the imaging lens group 70 of the seventh embodiment is shown in Table 18.

In the seventh embodiment, the numerical values of the relational expressions of the imaging lens group 70 are listed in Table 19. As can be seen from Table 19, the imaging lens group 70 of the seventh embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 7B, from left to right in the figure are longitudinal spherical aberration diagrams, astigmatic field curvature aberration diagrams, and distortion aberration diagrams of the imaging lens group 70, respectively. From the longitudinal spherical aberration diagram, it can be seen that three kinds of off-axis rays with different wavelengths of 486nm, 588nm and 656nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.04mm. From the astigmatic field curvature aberration diagram (wavelength 588nm), it can be seen that the change in the focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.06mm; the focal length of the aberration in the meridional direction is within the entire field of view The amount of change is within ± 0.06mm; and the distortion aberration can be controlled within 3%. As shown in FIG. 7B, the imaging lens group 70 of this embodiment has well corrected various aberrations, which meets the imaging quality requirements of the optical system.

Eighth embodiment

8A and 8B, FIG. 8A is a schematic diagram of an imaging lens group 80 according to an eighth embodiment of the present invention. 8B is a longitudinal spherical aberration diagram (Astigmatism / Field Curvature) and a distortion aberration diagram (Distortion) of the eighth embodiment of the present invention in order from left to right.

As shown in FIG. 8A, the imaging lens group 80 of the eighth embodiment sequentially includes an aperture ST, a first lens 81, a second lens 82, a third lens 83, a fourth lens 84, and a fifth lens from the object side to the image side. 85. The imaging lens group 80 may further include a filter element 86, a protective glass 87, and an imaging surface 88. An image sensing element 800 may be further disposed on the imaging surface 88 to constitute an imaging device (not otherwise labeled).

The first lens 81 has a negative refractive power, an object side surface 81a thereof is convex, an image side surface 81b is concave, and both the object side surface 81a and the image side surface 81b are spherical surfaces. The material of the first lens 81 is glass.

The second lens 82 has a positive refractive power, the object side surface 82a is a convex surface, the image side surface 82b is a convex surface, and both the object side surface 82a and the image side surface 82b are spherical surfaces. The material of the second lens 82 is glass.

The third lens 83 has a negative refractive power, and its object side surface 83a is convex (convex at the paraxial axis and concave at off-axis), its image side 83b is concave, and its object side 83a and image side 83b are aspheric. . The material of the third lens 83 is glass.

The fourth lens 84 has a positive refractive power, the object side surface 84a is a concave surface, the image side surface 84b is a convex surface, and both the object side surface 84a and the image side surface 84b are spherical surfaces. The material of the fourth lens 84 is glass.

The fifth lens 85 has a positive refractive power, the object side surface 85a is a convex surface, the image side surface 85b is a concave surface, and the object side surface 85a and the image side surface 85b are both spherical surfaces. The fifth lens 85 is made of glass.

The filter element 86 is disposed between the fifth lens 85 and the imaging surface 88 and is configured to filter out light in a specific wavelength range. The two surfaces 86a, 86b of the filter element 86 are both flat, and the material is glass.

The protective glass 87 is disposed on the image sensing element 800. The two surfaces 87a and 87b are both flat and the material is glass.

The image sensor 800 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor).

The detailed optical data and the aspheric coefficient of the lens surface of the imaging lens group 80 of the eighth embodiment are listed in Table 20 and Table 21, respectively. In the eighth embodiment, the curve equation of the aspherical surface is expressed as the first embodiment.

In the eighth embodiment, the values of the relational expressions of the imaging lens group 80 are listed in Table 22. As can be seen from Table 22, the imaging lens group 80 of the eighth embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 8B, from left to right in the figure are longitudinal spherical aberration diagrams, astigmatic field curvature aberration diagrams, and distortion aberration diagrams of the imaging lens group 80, respectively. From the longitudinal spherical aberration diagram, it can be seen that three types of off-axis rays with wavelengths of 900nm, 940nm, and 980nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.05mm. From the astigmatic field curvature aberration diagram (wavelength 940nm), it can be seen that the change in focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.06mm; the focal length of the aberration in the meridional direction is within the entire field of view The variation is within ± 0.05mm; and the distortion aberration can be controlled within 6%. As shown in FIG. 8B, the imaging lens group 80 of this embodiment has well corrected various aberrations, which meets the imaging quality requirements of the optical system.

Ninth embodiment

9A and 9B, FIG. 9A is a schematic diagram of an imaging lens group 90 according to a ninth embodiment of the present invention. FIG. 9B is a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration), an astigmatic field curvature aberration diagram (Astigmatism / Field Curvature), and a distortion aberration diagram (Distortion) of the ninth embodiment of the present invention in order from left to right.

As shown in FIG. 9A, the imaging lens group 90 of the ninth embodiment sequentially includes an aperture ST, a first lens 91, a second lens 92, a third lens 93, a fourth lens 94, and a fifth lens penetrator in order from the object side to the image side. 镜 95. The imaging lens group 90 may further include a filter element 96, a protective glass 97 and an imaging surface 98. An image sensing element 900 may be further disposed on the imaging surface 98 to form an imaging device (not otherwise labeled).

The first lens 91 has a negative refractive power, an object side surface 91a thereof is a concave surface, an image side surface 91b is a concave surface, and both the object side surface 91a and the image side surface 91b are spherical surfaces. The material of the first lens 91 is glass.

The second lens 92 has a positive refractive power, the object side surface 92a is a convex surface, the image side surface 92b is a convex surface, and both the object side surface 92a and the image side surface 92b are spherical surfaces. The material of the second lens 92 is glass.

The third lens 93 has a negative refractive power, and its object-side surface 93a is convex (convex at the paraxial and concave at the off-axis), its image-side 93b is concave, and its object-side 93a and image-side 93b are aspheric . The material of the third lens 93 is glass.

The fourth lens 94 has a positive refractive power. The object side surface 94a is a concave surface, the image side surface 94b is a convex surface, and both the object side surface 94a and the image side surface 94b are spherical surfaces. The material of the fourth lens 94 is glass.

The fifth lens 95 has a positive refractive power, and its object-side surface 95a is convex, and its image-side 95b is convex, and its object-side 95a and image-side 95b are spherical. The fifth lens 95 is made of glass.

The filter element 96 is disposed between the fifth lens 95 and the imaging surface 98 and is configured to filter out light in a specific wavelength range. The two surfaces 96a, 96b of the filter element 96 are both flat, and the material is glass.

The protective glass 97 is disposed on the image sensing element 900. The two surfaces 97a and 97b are both flat and the material is glass.

The image sensor 900 is, for example, a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor image sensor (CMOS Image Sensor).

The detailed optical data of the imaging lens group 90 of the ninth embodiment and the aspheric coefficient of the lens surface are listed in Tables 23 and 24, respectively. In the ninth embodiment, the curve equation of the aspherical surface is expressed as the first embodiment.

In the ninth embodiment, the values of the relational expressions of the imaging lens group 90 are listed in Table 25. As can be seen from Table 25, the imaging lens group 90 of the ninth embodiment satisfies the requirements of the relational expressions (1) to (13).

Referring to FIG. 9B, from left to right in the figure are longitudinal spherical aberration diagrams, astigmatic field curvature aberration diagrams, and distortion aberration diagrams of the imaging lens group 90, respectively. From the longitudinal spherical aberration diagram, it can be seen that three types of off-axis rays with wavelengths of 900nm, 940nm, and 980nm at different heights can be concentrated near the imaging point, and the deviation of the imaging point can be controlled within ± 0.05mm. From the astigmatic field curvature aberration diagram (wavelength 940nm), it can be seen that the change in focal length of the aberration in the sagittal direction within the entire field of view is within ± 0.09mm; the focal length of the aberration in the meridional direction is within the entire field of view The amount of change is within ± 0.08mm; and the distortion aberration can be controlled within 6%. As shown in FIG. 9B, the imaging lens group 90 of this embodiment has well corrected various aberrations, and meets the imaging quality requirements of the optical system.

Tenth embodiment

The tenth embodiment of the present invention is an imaging device. The imaging device includes the imaging lens group as described in the first to ninth embodiments, and an image sensing element. Charge-coupled Device (Charge-Coupled Device, CCD) or Complementary Metal Oxide Semiconductor (Complementary Metal Oxide Semiconductor, CMOS) image sensor. The imaging device is, for example, a camera module for automotive photography, a camera module for portable electronic products, or a camera module for a surveillance camera.

Eleventh embodiment

Please refer to FIG. 10, which is a schematic diagram of an electronic device 1000 according to an eleventh embodiment of the present invention. As shown, the electronic device 1000 includes an imaging device 1010 and a near-infrared emitting element 1020. The imaging device 1010 is, for example, the imaging device of the tenth embodiment described above, and may be composed of the imaging lens group and an image sensing element of the present invention. The near-infrared emitting element 1020 is, for example, a near-infrared lamp for emitting a near-infrared light beam with a wavelength of 940 nm. The electronic device 1000 is, for example, a driving monitoring device or a surveillance camera.

Although the present invention is described using the foregoing embodiments, the embodiments are not intended to limit the scope of the present invention. For anyone skilled in the art, without departing from the spirit and scope of the present invention, various changes in form and details can still be made with reference to the content of the embodiments disclosed in the present invention. Therefore, it should be understood here that the present invention is subject to the definitions of the following patent application scopes. Any changes made within the scope of the patent application or its equivalent scope shall still fall into the application of the present invention Within the scope of the patent.

Claims (19)

An imaging lens group includes, in order from the object side to the image side, an aperture; a first lens having a negative refractive power and its image side is concave; a second lens having a positive refractive power; a third lens having a A negative refractive power; a fourth lens having a meniscus lens with a positive refractive power, the object side of which is concave and a convex image side; and a fifth lens having a positive refractive power, whose object side is convex; wherein, the The total number of lenses of the imaging lens group is five; the combined focal length of the first lens and the second lens is f12, the effective focal length of the imaging lens group is EFL, and the imaging surface of the first lens object side to the imaging lens group is at The distance on the optical axis is TTL, which satisfies the following relations: 0.5 <f12 / EFL <1.6; and 1.8 <TTL / EFL <2.6. For example, the imaging lens group of the first patent application range, wherein the imaging lens group satisfies the following relationship: 0.2 <f3 / f1 <0.7; where f1 is the focal length of the first lens and f3 is the focal length of the third lens. focal length. The imaging lens group of the first patent application range, wherein the imaging lens group includes at least two lenses having a refractive index greater than 1.7. The imaging lens group of the first patent application range, wherein the refractive index of the second lens is Nd2, which satisfies the following relationship: Nd2> 1.75. For example, the imaging lens group of the first patent application scope, wherein the object side and the image side of the third lens are aspheric, and the material of the third lens is glass. For example, the imaging lens group of the first patent application scope, wherein the object side of the third lens is convex at the near optical axis. For example, the imaging lens group of the first patent application scope, wherein the object side and the image side of the second lens are convex. For example, the imaging lens group of the first patent application range, wherein the imaging lens group satisfies the following relationship: 3.8 <TTL / ImgH <5.1; where ImgH is the maximum image height of the imaging lens group. For example, the imaging lens group of the first patent application range, wherein the imaging lens group satisfies the following relationship: 0.4 <f2 / EFL <0.9; where f2 is the focal length of the second lens. For example, the imaging lens group of the first patent application range, wherein the imaging lens group satisfies the following relationship: 0.9 <f4 / EFL <1.6; where f4 is the focal length of the fourth lens. For example, the imaging lens group of the first patent application range, wherein the imaging lens group satisfies the following relationship: 1.3 <f5 / EFL <6; where f5 is the focal length of the fifth lens. For example, the imaging lens group of the first patent application range, wherein the imaging lens group satisfies the following relationship: 0.7 <AT34 / (AT12 + AT23 + AT45) <4.3; where AT12 is the image side of the first lens to the first lens The distance between the two lens object sides on the optical axis, AT23 is the distance between the second lens image side to the third lens object side on the optical axis, and AT34 is the third lens image side to the fourth lens object side on the light axis. The distance on the axis, AT45 is the distance on the optical axis from the image side of the fourth lens to the object side of the fifth lens. An imaging lens group includes, in order from the object side to the image side: an aperture; a first lens having a negative refractive power and its image side is concave; a second lens having a positive refractive power, wherein the first lens The combined focal length of the second lens and the second lens is a positive value; a third lens has a negative refractive power; a fourth lens has a positive refractive power; its object side is concave and its image side is convex; and a fifth lens, It has positive refractive power and its object side is convex; the total number of lenses of the imaging lens group is five; the focal length of the second lens is f2; the effective focal length of the imaging lens group is EFL; the first lens object side to the imaging The distance of the imaging surface of the lens group on the optical axis is TTL, and the maximum image height of the imaging lens group is ImgH; the imaging lens group satisfies the following relations: 0.4 <f2 / EFL <0.9; and 3.8 <TTL / ImgH <5.1 . For example, the imaging lens group of the first or the thirteenth patent application scope, wherein the fourth lens system satisfies the following relationship: 0.25 <R8 / R7 <0.6; where R7 is the radius of curvature of the object side of the fourth lens, R8 is the curvature radius of the image side of the fourth lens. For example, the imaging lens group of the scope of application for item 14, wherein the imaging lens group satisfies the following relationship: 0.11 <CT4 / TTL <0.19; where CT4 is the thickness of the fourth lens. For example, the imaging lens group of the first or the thirteenth patent application scope, wherein the curvature of the object side of the fifth lens is C9 and the curvature of the image side is C10, which satisfies the following relationship: 0.7 <(C9 + C10) / (C9-C10) <2.5. For example, the imaging lens group of the 16th scope of the application for a patent, wherein the imaging lens group satisfies the following relationship: 0.03 <CT5 / TTL <0.1; where CT5 is the thickness of the fifth lens. An imaging device includes an imaging lens group such as item 1 or item 13 of the patent application scope, and an image sensing element. An electronic device includes the imaging device according to item 18 of the scope of patent application.