TWI680323B - Wide-angle imaging lens, imaging device and electronic device having the same - Google Patents

Abstract

The invention provides a wide-angle imaging lens group, and an imaging device and an electronic device having the wide-angle imaging lens group. This wide-angle imaging lens group includes a first lens with a negative refractive power in order from the object side to the image side. The object side is convex and the image side is concave, an aperture, and a second lens with positive refractive power. Its object side is convex, a third lens with positive refractive power, its image side is convex, and a fourth lens with negative refractive power, its object side is concave, and its image side is convex. When this wide-angle imaging lens group meets certain conditions, it can balance the lens's refractive power, effectively shorten the total length of the system, and correct aberrations to provide better-quality wide-angle imaging.

Description

Wide viewing angle imaging lens group, imaging device and electronic device thereof

The invention relates to a wide-view imaging device, in particular to a wide-view imaging lens group which can be used in a portable electronic device, a medical photography device or a car photography device, and an imaging device and an electronic device having the wide-view imaging lens group. Device.

With the advancement of semiconductor manufacturing technology, the size of photosensitive elements (such as CCD and CMOS Image Sensor) required for photographic devices can be reduced and meet the requirements of miniaturized photographic devices. Therefore, consumer electronics products have been equipped with miniaturized cameras. ) To improve the development trend of product added value. Taking a portable electronic device such as a mobile phone as an example, because of its convenience and portability, today's consumers mostly use mobile phones to take pictures to replace the habit of using traditional digital cameras. However, consumers are increasingly demanding portable electronic devices, and they are also seeking for small size and light weight in addition to the beautiful appearance. Therefore, this trend makes it necessary for the small-sized photographic device mounted on the portable electronic device to be further miniaturized in terms of the overall size, so as to be able to be accommodated in light, thin and short electronic products.

In addition, consumers are increasingly demanding the photographic functions of portable electronic products, coupled with the diversified development of optical lens applications, such as automotive photography devices, image recognition systems, smart home assistance systems, and AR / VR entertainment products. However, the perspective of taking pictures provided by traditional miniaturized photography devices has gradually failed to meet the needs of consumers, and has been moving towards a wider perspective. However mention A high angle of view of the photographic device will reduce the resolution of the imaging quality, and a wide-angle imaging device usually uses a lens with a negative refractive power at the position of the first lens to increase the light receiving range. In order to correct aberrations caused by wide-angle incident light, Additional lenses are required to correct the aberrations, and various factors will increase the total lens length of the wide-angle imaging device.

Therefore, how to provide a miniaturized wide-view imaging device has become a problem that people in this technical field want to solve.

The invention provides a wide-angle imaging lens group, which sequentially includes: a first lens with a negative refractive power, an aperture, a second lens with a positive refractive power, and a first lens with a positive refractive power. Three lenses, and a fourth lens with negative refractive power. The first lens includes an object side and an image side, and the object side of the first lens is convex, and the image side of the first lens is concave; the second lens includes an object side and an image side, and the second lens The object side is convex; the third lens includes an object side and an image side, and the image side of the third lens is convex; and the fourth lens includes an object side and an image side, and the object side of the fourth lens is concave, The image side of the fourth lens is convex.

This wide-angle imaging lens group satisfies the following conditions: 0.5 <| f1 / f2 | <1.2; and 0.1 <| f / f4 | <1.2.

Among them, f is the effective focal length of the wide-angle imaging lens group, f1 is the focal length of the first lens, f2 is the focal length of the second lens, and f4 is the focal length of the fourth lens.

According to an embodiment of the present invention, the thicknesses of the first lens to the fourth lens on the optical axis are CT1, CT2, CT3, and CT4, respectively, and the image side of the first lens and the second lens The distance of the object side on the optical axis is AT1, and the wide-angle imaging lens group satisfies the following conditions: 0.1 <AT1 / (CT1 + CT2 + CT3 + CT4) <0.42.

According to an embodiment of the present invention, the curvature radii of the object side and the image side of the first lens are R1 and R2, respectively, and the wide-angle imaging lens group satisfies the following conditions: 1 <(R1 + R2) / (R1-R2) <2.7.

According to an embodiment of the present invention, the dispersion coefficient of the third lens is V3, the dispersion coefficient of the fourth lens is V4, and the wide-angle imaging lens group satisfies the following conditions: 0.2 <V4 / V3 <0.5.

According to an embodiment of the present invention, one half of the maximum viewing angle of the wide-angle imaging lens group is HFOV, which satisfies the following conditions: 45 degrees <HFOV <85 degrees.

According to an embodiment of the present invention, the image side of the second lens is convex.

According to an embodiment of the present invention, the image side of the second lens is concave at a distance from the optical axis.

According to an embodiment of the present invention, the image side of the second lens is concave.

According to an embodiment of the present invention, the object side of the third lens is convex.

According to an embodiment of the present invention, the object sides and the image sides of the first lens to the fourth lens are aspheric surfaces.

According to an embodiment of the present invention, wherein the wide-angle imaging lens group further satisfies the following condition: 0.1 <| f / f4 | <1.

The present invention further provides an imaging device including the wide-angle imaging lens as described above. Mirror Group.

The present invention further provides an electronic device including the imaging device as described above.

10, 20, 30, 40, 50, 60‧‧‧ wide-angle imaging lens group

11, 21, 31, 41, 51, 61‧‧‧ first lens

12, 22, 32, 42, 52, 62‧‧‧Second lens

13, 23, 33, 43, 53, 63, ‧‧‧ third lens

14, 24, 34, 44, 54, 64‧‧‧ Fourth lens

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

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

12a, 22a, 32a, 42a, 52a, 62a ‧‧‧ the side of the object of the second lens

12b, 22b, 32b, 42b, 52b, 62b ‧‧‧ side of the image of the second lens

13a, 23a, 33a, 43a, 53a, 63a ‧‧‧ object side of the third lens

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

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

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

15, 25, 35, 45, 55, 65‧‧‧ filter elements

16, 26, 36, 46, 56, 66‧‧‧‧ imaging surface

17, 27, 37, 47, 57, 67‧‧‧ Protective glass

I‧‧‧ Optical axis

ST‧‧‧ aperture

100, 200, 300, 400, 500, 600‧‧‧ electronic photosensitive elements

FIG. 1A is a schematic diagram of a wide-angle imaging lens group according to a first embodiment of the present invention.

FIG. 1B is a longitudinal spherical aberration diagram of the first embodiment of the present invention.

FIG. 1C is a field curvature aberration diagram of the first embodiment of the present invention.

FIG. 1D is a distortion aberration diagram of the first embodiment of the present invention.

FIG. 2A is a schematic diagram of a wide-angle imaging lens group according to a second embodiment of the present invention.

FIG. 2B is a longitudinal spherical aberration diagram of the second embodiment of the present invention.

FIG. 2C is a field curvature aberration diagram of the second embodiment of the present invention.

FIG. 2D is a distortion aberration diagram of the second embodiment of the present invention.

FIG. 3A is a schematic diagram of a wide-angle imaging lens group 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.

FIG. 3C is a field curvature aberration diagram of the third embodiment of the present invention.

FIG. 3D is a distortion aberration diagram of the third embodiment of the present invention.

FIG. 4A is a schematic diagram of a wide-angle imaging lens group 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.

FIG. 4C is a field curvature aberration diagram of the fourth embodiment of the present invention.

FIG. 4D is a distortion aberration diagram of the fourth embodiment of the present invention.

FIG. 5A is a schematic diagram of a wide-angle imaging lens group 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.

FIG. 5C is a field curvature aberration diagram of the fifth embodiment of the present invention.

FIG. 5D is a distortion aberration diagram of the fifth embodiment of the present invention.

FIG. 6A is a schematic diagram of a wide-angle imaging lens group according to a sixth embodiment of the present invention.

FIG. 6B is a longitudinal spherical aberration diagram of a sixth embodiment of the present invention.

FIG. 6C is a field curvature aberration diagram of a sixth embodiment of the present invention.

FIG. 6D is a distortion aberration diagram of the sixth embodiment of the present invention.

The wide-angle imaging lens group of the present invention sequentially includes a first lens, a diaphragm, a second lens, a third lens, and a fourth lens from the object side to the image side.

In the embodiment of the present invention, each lens includes an object side facing an object and an image side facing an imaging surface. Each of the object side and the image side includes a surface area near the optical axis and a surface area far from the optical axis. In the following description, the shape of the surface of each lens is convex or concave. If it is not explicitly specified at the paraxial or far from the optical axis, the shape of the surface area at the paraxial is convex or concave.

The first lens of the wide-angle imaging lens group of the present invention has a negative refractive power, and a surface near the object side (object side) is convex, and a surface near the image side (image side) is concave. Thereby, it is possible to receive incident light with a larger angle range, and increase the light receiving range of the imaging lens group.

The second lens has a positive refractive power, and its object side is convex. The third lens has a positive refractive power, and its image side is convex. Thereby, the negative refractive power of the first lens can be balanced. The aperture is disposed between the first lens and the second lens to reduce stray light. The focal length of the first lens is f1, and the focal length of the second lens is f2, and the following conditions are satisfied: 0.5 <| f1 / f2 | <1.2. By appropriately configuring the focal length of the first lens and the second lens, it helps to reduce the overall length of the wide-angle imaging lens group and increase the overall length. Lighting effect.

The fourth lens has a negative refractive power, and its object side is concave and its image side is convex. By designing the first lens and the fourth lens to have a negative refractive power, and the second lens and the third lens to have a positive refractive power, the field angle and the field curvature can be effectively enlarged. The effective focal length of the wide-angle imaging lens group is f, and the focal length of the fourth lens is f4, and the following conditions are satisfied: 0.1 <| f / f4 | <1.2. Preferably, the wide-angle imaging lens group satisfies the following condition: 0.1 <| f / f4 | <1. By appropriately configuring the ratio between the effective focal length of the wide-angle imaging lens group and the focal length of the fourth lens, it is possible to help correct astigmatism.

The distance between the image side of the first lens and the object side of the second lens on the optical axis is AT1, and the thicknesses of the first to fourth lenses on the optical axis are CT1, CT2, CT3, and CT4, which can meet the following Conditions: 0.1 <AT1 / (CT1 + CT2 + CT3 + CT4) <0.42. Thereby, the curvature or the outer diameter of the first lens can be prevented from being too large, and the distortion can be effectively corrected.

The curvature radius of the object side of the first lens is R1, and the curvature radius of its image side is R1, which can satisfy the following conditions: 1 <(R1 + R2) / (R1-R2) <2.7. Thereby, the curvature or the outer diameter of the first lens can be prevented from being too large, and the aberration can be effectively corrected.

The dispersion coefficient of the third lens is V3, and the dispersion coefficient of the fourth lens is V4, which can satisfy the following conditions: 0.2 <V4 / V3 <0.5. Thereby, the chromatic aberration of the wide-angle imaging lens group can be effectively corrected.

Half of the maximum viewing angle of the wide-angle imaging lens group is HFOV (Half Field of View), which satisfies the following conditions: 45 degrees <HFOV <85 degrees.

<First Embodiment>

FIG. 1A is a schematic diagram of a wide-angle imaging lens group according to a first embodiment of the present invention. FIG. 1B is a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) of the wide-angle imaging lens group according to the first embodiment of the present invention. FIG. 1C is a Field Curve aberration diagram of the wide-angle imaging lens group according to the first embodiment of the present invention. FIG. 1D is a distortion aberration diagram of the wide-angle imaging lens group according to the first embodiment of the present invention.

As shown in FIG. 1A, the wide-angle imaging lens group 10 of the first embodiment includes a first lens 11, a diaphragm ST, a second lens 12, a third lens 13, a fourth lens 14, Filter element 15 and imaging surface 16. Wherein, the object side is close to one side of the object to be photographed, and the image side is close to one side of the imaging surface 16; a cover glass 17 may be provided on one side of the imaging surface 16. The wide-angle imaging lens group 10 can be further equipped with an electronic photosensitive element 100 (disposed on the imaging surface 16) to form a wide-angle imaging device (not otherwise labeled).

The first lens 11 has a negative refractive power and is made of glass. The first lens 11 has an object side surface 11a facing the object side and an image side surface 11b facing the image side. The object side surface 11a is a convex surface and the image side surface 11b is a concave surface. The two surfaces 11a and 11b are aspherical surfaces.

The second lens 12 has a positive refractive power and is made of plastic. The second lens 12 has an object side surface 12a facing the object side and an image side surface 12b facing the image side, wherein the object side surface 12a is a convex surface and the image side surface 12b is a convex surface, and both surfaces 12a and 12b are aspherical surfaces.

The third lens 13 has a positive refractive power and is made of plastic. The third lens 13 has an object side surface 13a facing the object side and an image side surface 13b facing the image side. The two surfaces 13a and 13b are both aspherical surfaces. Among them, the object side surface 13a of the third lens 13 is convex at the near optical axis (labeled I in the figure) and concave at a distance from the optical axis; and the image side 13b is convex at the near optical axis and at a distance from the optical axis. Is convex.

The fourth lens 14 has a negative refractive power and is made of plastic. The fourth lens 14 has an object side surface 14a facing the object side and an image side surface 14b facing the image side. The object side surface 14a is a concave surface and the image side surface 14b is a convex surface. The two surfaces 14a and 14b are aspheric surfaces.

The filter element 15 is disposed between the fourth lens 14 and the imaging surface 16. The material of the filter element 15 is glass, and the surfaces 15 a and 15 b are both flat. The filter element 15 is, for example, an infrared filter (IR Filter).

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

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

The effective focal length of the wide-angle imaging lens group 10 of the first embodiment is f, the aperture value (F-number) is Fno, the total system length (Total Track Length) is TTL, and one-half of the maximum viewing angle is HFOV (Half Field of View). The values are as follows: f = 0.761mm, Fno = 3.4, TTL = 2.87mm, HFOV = 59.75 degrees.

The focal length of the first lens 11 is f1, and the focal length of the second lens 12 is f2, which satisfies the following conditions: | f1 / f2 | = 1.008.

The focal length of the fourth lens 14 is f4, which satisfies the following conditions: | f / f4 | = 0.132.

The thicknesses of the first lens 11 to the fourth lens 14 on the optical axis I are CT1 and CT1, respectively. CT2, CT3 and CT4, the distance between the image side 11b of the first lens 11 and the object side 12a of the second lens 12 on the optical axis I is AT1, which meets the following conditions: AT1 / (CT1 + CT2 + CT3 + CT4) = 0.307.

The curvature radii of the object side 11a and the image side 11b of the first lens 11 are R1 and R2, respectively, which satisfy the following conditions: (R1 + R2) / (R1-R2) = 2.619.

The dispersion coefficient of the third lens 13 is V3, and the dispersion coefficient of the fourth lens 14 is V4, which satisfies the following conditions: V4 / V3 = 0.383.

Please refer to Table 1 below for detailed optical data of the wide-angle imaging lens group according to the first embodiment of the present invention. Among them, the object side 11a of the first lens 11 is labeled as the surface 11a, the image side 11b is labeled as the surface 11b, and the other lens surfaces are deduced by analogy; the lens surface labeled as ASP in the table, such as the object side 11a of the first lens 11a , It means that the surface is aspherical; if the surface of the lens whose ASP is not marked in the table, it means that the surface is spherical. The value in the distance field in the table represents the distance from the surface to the next surface. For example, the distance from the object side 11a to the image side 11b of the first lens 11 is 0.228 mm, which represents the thickness of the first lens 11 is 0.228 mm. The distance from the image side 11b of the first lens 11 to the aperture is 0.4 mm. The distance from the image side 12b of the second lens 12 to the object side 13a of the third lens 13 is 0.104 mm. Others can be deduced by analogy, which will not be repeated below.

Please refer to Table 2, which shows the aspheric coefficients of the surfaces of the lenses of the first embodiment of the present invention. Among them, K is the cone coefficient in the aspheric curve equation, and A2 to A16 represent the aspheric coefficients of the 2nd to 16th order of each surface. For example, the taper coefficient K of the object side surface 11a of the first lens 11 is -0.0864. Others can be deduced by analogy, which will not be repeated below. In addition, the tables of the following embodiments correspond to the wide-view imaging lens groups of the embodiments, and the definitions of the tables are the same as those of the first embodiment, so they will not be repeated in the following embodiments.

<Second Embodiment>

FIG. 2A is a schematic diagram of a wide-angle imaging lens group according to a second embodiment of the present invention. FIG. 2B is a longitudinal spherical aberration diagram of a wide-angle imaging lens group according to a second embodiment of the present invention. FIG. 2C is a Field Curve aberration diagram of a wide-angle imaging lens group according to a second embodiment of the present invention. FIG. 2D is a distortion aberration diagram of the wide-angle imaging lens group according to the second embodiment of the present invention.

As shown in FIG. 2A, the wide-angle imaging lens group 20 of the second embodiment includes a first lens 21, an aperture ST, a second lens 22, a third lens 23, a fourth lens 24, and the like in order from the object side to the image side. Filter element 25 and imaging surface 26. A protective glass 27 may be disposed on one side of the imaging surface 26. The wide-angle imaging lens group 20 can also be combined with an electronic photosensitive element 200 (set on the imaging surface 26) to form a wide-angle imaging device (not otherwise labeled).

The first lens 21 has a negative refractive power and is made of glass. The first lens 21 has an object side surface 21a facing the object side and an image side surface 21b facing the image side, wherein the object side surface 21a is a convex surface and the image side surface 21b is a concave surface, and both surfaces 21a and 21b are aspherical surfaces.

The second lens 22 has a positive refractive power and is made of glass. The second lens 22 has an object side surface 22a facing the object side and an image side surface 22b facing the image side. The object side surface 22a is a convex surface and the image side surface 22b is a concave surface. The two surfaces 22a and 22b are spherical surfaces.

The third lens 23 has a positive refractive power and is made of plastic. The third lens 23 has an object side surface 23a facing the object side and an image side surface 23b facing the image side. Among them, the object side surface 23a of the third lens 23 is convex and the image side surface 23b is convex. Aspherical. .

The fourth lens 24 has a negative refractive power and is made of plastic. The fourth lens 24 has an object side surface 24a facing the object side and an image side surface 24b facing the image side. The object side surface 24a is a concave surface. The image side surface 24b is convex, and both surfaces 24a and 24b are aspherical.

The filter element 25 is disposed between the fourth lens 24 and the imaging surface 26. The material of the filter element 25 is glass, and the surfaces 25 a and 25 b are both flat. The filter element 25 is, for example, an infrared filter (IR Filter).

The parameters of the wide-angle imaging lens group 20 of the second embodiment are the same as those of the first embodiment. For example, the effective focal length is f, the aperture value (F-number) is Fno, and one-half of the maximum viewing angle is HFOV. For values, see Table 3.

Secondly, please refer to Tables 4 and 5 below. Among them, Table 4 is the detailed optical data of the wide-angle imaging lens group in the second embodiment of the present invention, and Table 5 is the aspheric coefficient of each lens surface in the second embodiment of the present invention. .

<Third Embodiment>

FIG. 3A is a schematic diagram of a wide-angle imaging lens group according to a third embodiment of the present invention. FIG. 3B is a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) of the wide-angle imaging lens group according to the third embodiment of the present invention. FIG. 3C is a Field Curve aberration diagram of a wide-angle imaging lens group according to a third embodiment of the present invention. FIG. 3D is a distortion aberration diagram of the wide-angle imaging lens group according to the third embodiment of the present invention.

As shown in FIG. 3A, the wide-angle imaging lens group 30 of the third embodiment includes a first lens 31, an aperture ST, a second lens 32, a third lens 33, a fourth lens 34, and Filter element 35 and imaging surface 36. A protective glass 37 may be disposed on one side of the imaging surface 36. The wide-angle imaging lens group 30 can be further equipped with an electronic photosensitive element 300 (disposed on the imaging surface 36) to form a wide-angle imaging device (not otherwise labeled).

The first lens 31 has a negative refractive power and is made of glass. The first lens 31 has an object side surface 31a facing the object side and an image side surface 31b facing the image side, wherein the object side surface 31a is a convex surface and the image side surface 31b is a concave surface, and both surfaces 31a and 31b are aspherical surfaces.

The second lens 32 has a positive refractive power and is made of plastic. The second lens 32 has an object side surface 32a facing the object side and an image side surface 32b facing the image side, wherein the object side surface 32a is a convex surface and the image side surface 32b is a convex surface, and both surfaces 32a and 32b are aspherical surfaces.

The third lens 33 has a positive refractive power and is made of plastic. The third lens 33 has an object side 33a facing the object side and an image side 33b facing the image side. Among them, the object side 33a of the third lens 33 is convex, and the image side 33b is convex, and both surfaces 33a and 33b are Aspherical.

The fourth lens 34 has a negative refractive power and is made of plastic. The fourth lens 34 has an object side surface 34a facing the object side and an image side surface 34b facing the image side, and both surfaces 34a and 34b are aspherical surfaces. Among them, the object side surface 34a is concave at the near optical axis and concave at a distance from the optical axis, and the image side 34b is convex at the near optical axis and is concave at a distance from the optical axis.

The filter element 35 is disposed between the fourth lens 34 and the imaging surface 36. The material of the filter element 35 is glass, and the surfaces 35 a and 35 b are both flat. The filter element 35 is, for example, an infrared filter (IR Filter).

The definitions of the parameters of the wide-angle imaging lens group 30 of the third embodiment are the same as those of the first embodiment, for example, the effective focal length is f, the aperture value (F-number) is Fno, and one of the maximum viewing angles Half is HFOV, etc. Please refer to Table 6 for related parameter values.

Secondly, please refer to Tables 7 and 8 below. Among them, Table 7 is the detailed optical data of the wide-angle imaging lens group in the third embodiment of the present invention, and Table 8 is the aspheric coefficient of each lens surface in the third embodiment of the present invention. .

<Fourth embodiment>

FIG. 4A is a schematic diagram of a wide-angle imaging lens group according to a fourth embodiment of the present invention. FIG. 4B is a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) of the wide-angle imaging lens group according to the fourth embodiment of the present invention. FIG. 4C is a Field Curve aberration diagram of a wide-angle imaging lens group according to a fourth embodiment of the present invention. FIG. 4D is a distortion aberration diagram of a wide-angle imaging lens group according to a fourth embodiment of the present invention.

As shown in FIG. 4A, the wide-angle imaging lens group 40 of the fourth embodiment includes a first lens 41, an aperture ST, a second lens 42, a third lens 43, a fourth lens 44, Filter element 45 and imaging surface 46. A protective glass may be provided on one side of the imaging surface 46. Glass 47. The wide-angle imaging lens group 40 can be further equipped with an electronic photosensitive element 400 (disposed on the imaging surface 46) to form a wide-angle imaging device (not otherwise labeled).

The first lens 41 has a negative refractive power and is made of plastic. The first lens 41 has an object side surface 41a facing the object side and an image side surface 41b facing the image side. The object side surface 41a is a convex surface and the image side surface 41b is a concave surface. The two surfaces 41a and 41b are aspheric surfaces.

The second lens 42 has a positive refractive power and is made of plastic. The second lens 42 has an object side surface 42a facing the object side and an image side surface 42b facing the image side, wherein the object side surface 42a is a convex surface and the image side surface 42b is a convex surface, and both surfaces 42a and 42b are spherical surfaces.

The third lens 43 has a positive refractive power and is made of plastic. The third lens 43 has an object side surface 43a facing the object side and an image side surface 43b facing the image side. Among them, the object side surface 43a of the third lens 43 is convex and the image side surface 43b is convex, and both surfaces 43a and 43b are Aspherical. .

The fourth lens 44 has a negative refractive power and is made of plastic. The fourth lens 44 has an object side surface 44a facing the object side and an image side surface 44b facing the image side, wherein the object side surface 44a is a concave surface and the image side surface 44b is a convex surface, and both surfaces 44a and 44b are aspherical surfaces.

The filter element 45 is disposed between the fourth lens 44 and the imaging surface 46. The material of the filter element 45 is glass, and the surfaces 45a and 45b are both flat. The filter element 45 is, for example, an infrared filter (IR Filter).

The parameters of the wide-angle imaging lens group 40 of the fourth embodiment are the same as those of the first embodiment. For example, the effective focal length is f, the aperture value (F-number) is Fno, and one-half of the maximum viewing angle is HFOV. See Table 9 for values.

Secondly, please refer to Tables 10 and 11 below. Among them, Table 10 is the detailed optical data of the wide-angle imaging lens group of the fourth embodiment of the present invention, and Table 11 is the non-linearity of each lens surface of the fourth embodiment of the present invention. Spherical coefficient.

<Fifth Embodiment>

FIG. 5A is a schematic diagram of a wide-angle imaging lens group according to a fifth embodiment of the present invention. 5B is a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) of a wide-angle imaging lens group according to a fifth embodiment of the present invention. FIG. 5C is a Field Curve aberration diagram of a wide-angle imaging lens group according to a fifth embodiment of the present invention. FIG. 5D is a distortion aberration diagram of a wide-angle imaging lens group according to a fifth embodiment of the present invention.

As shown in FIG. 5A, the wide-angle imaging lens group 50 of the fifth embodiment includes a first lens 51, an aperture ST, a second lens 52, a third lens 53, and a fourth lens in order from the object side to the image side. Mirror 54, filter element 55, and imaging surface 56. A protective glass 57 may be disposed on one side of the imaging surface 56. The wide-angle imaging lens group 50 can be further equipped with an electronic photosensitive element 500 (disposed on the imaging surface 56) to form a wide-angle imaging device (not otherwise labeled).

The first lens 51 has a negative refractive power and is made of plastic. The first lens 51 has an object side surface 51a facing the object side and an image side surface 51b facing the image side, wherein the object side surface 51a is a convex surface and the image side surface 51b is a concave surface, and both surfaces 51a and 51b are aspherical surfaces.

The second lens 52 has a positive refractive power and is made of plastic. The second lens 52 has an object side surface 52a facing the object side and an image side surface 52b facing the image side, wherein the object side surface 52a is a convex surface and the image side surface 52b is a concave surface, and both surfaces 52a and 52b are aspherical surfaces.

The third lens 53 has a positive refractive power and is made of plastic. The third lens 53 has an object side surface 53a facing the object side and an image side surface 53b facing the image side. Among them, the object side surface 53a of the third lens 53 is convex and the image side surface 53b is convex, and the two surfaces 53a and 53b are both Aspherical. .

The fourth lens 54 has a negative refractive power and is made of plastic. The fourth lens 54 has an object side surface 54a facing the object side and an image side surface 54b facing the image side. Among them, the object side surface 54a is a concave surface and the image side surface 54b is a convex surface, and both surfaces 54a and 54b are aspherical surfaces.

The filter element 55 is disposed between the fourth lens 54 and the imaging surface 56. The material of the filter element 55 is glass, and the surfaces 55 a and 55 b are both flat. The filter element 55 is, for example, an infrared filter (IR Filter).

The parameters of the wide-angle imaging lens group 50 of the fifth embodiment are the same as those of the first embodiment. For example, the effective focal length is f, the aperture value (F-number) is Fno, and one-half of the maximum viewing angle is HFOV. Related parameters For values, see Table 12.

Secondly, please refer to Tables 13 and 14 below. Among them, Table 13 is the detailed optical data of the wide-angle imaging lens group of the fifth embodiment of the present invention, and Table 14 is the surface of each lens of the fifth embodiment of the present invention. Aspheric coefficient.

<Sixth embodiment>

FIG. 6A is a schematic diagram of a wide-angle imaging lens group according to a sixth embodiment of the present invention. FIG. 6B is a longitudinal spherical aberration diagram (Longitudinal Spherical Aberration) of the wide-angle imaging lens group according to the sixth embodiment of the present invention. FIG. 6C is a field aberration diagram of a wide-angle imaging lens group according to a sixth embodiment of the present invention. FIG. 6D is a wide-angle imaging lens group according to a sixth embodiment of the present invention. Distortion aberration diagram.

As shown in FIG. 6A, the wide-angle imaging lens group 60 of the sixth embodiment includes a first lens 61, an aperture ST, a second lens 62, a third lens 63, a fourth lens 64, and the like in order from the object side to the image side. Filter element 65 and imaging surface 66. A protective glass 67 may be disposed on one side of the imaging surface 66. The wide-angle imaging lens group 60 can be further equipped with an electronic photosensitive element 600 (disposed on the imaging surface 66) to form a wide-angle imaging device (not otherwise labeled).

The first lens 61 has a negative refractive power and is made of plastic. The first lens 61 has The object side surface 61a facing the object side and the image side surface 61b facing the image side, wherein the object side surface 61a is a convex surface and the image side surface 61b is a concave surface, and both surfaces 61a and 61b are aspherical surfaces.

The second lens 62 has a positive refractive power and is made of glass. The second lens 62 has an object side surface 62a facing the object side and an image side surface 62b facing the image side, and both surfaces 62a and 62b are aspherical surfaces. Among them, the object side surface 62 is convex on the near optical axis, and convex on the far optical axis, and the image side 62b is convex on the near optical axis, and is concave on the far optical axis.

The third lens 63 has a positive refractive power and is made of plastic. The third lens 63 has an object side 63a facing the object side and an image side 63b facing the image side. Among them, the object side 63a of the third lens 63 is convex, and the image side 63b is convex, and both surfaces 63a and 63b are Aspherical.

The fourth lens 64 has a negative refractive power and is made of plastic. The fourth lens 64 has an object side 64a facing the object side and an image side 64b facing the image side. The object side 64a is a concave surface and the image side 64b is a convex surface. The two surfaces 64a and 64b are aspherical surfaces.

The filter element 65 is disposed between the fourth lens 64 and the imaging surface 66. The material of the filter element 65 is glass, and the surfaces 65a and 65b are both flat. The filter element 65 is, for example, an infrared filter (IR Filter).

The parameters of the wide-angle imaging lens group 60 of the sixth embodiment are the same as those of the first embodiment. For example, the effective focal length is f, the aperture value (F-number) is Fno, and one-half of the maximum viewing angle is HFOV. Related parameters For values, see Table 15.

Secondly, please refer to Tables 16 and 17 below. Among them, Table 16 is the detailed optical data of the wide-angle imaging lens group of the sixth embodiment of the present invention, and Table 17 is the surface of each lens of the sixth embodiment of the present invention. Aspheric coefficient.

<Seventh Embodiment>

A seventh embodiment of the present invention is an imaging device (not shown). The imaging device includes the wide-angle imaging lens group as in the foregoing embodiment, and an electronic photosensitive element.

<Eighth Embodiment>

An eighth embodiment of the present invention is an electronic device (not shown). The electronic device includes an imaging device as the seventh embodiment.

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. It should be understood here that the present invention is defined by the following patent application scope, and any changes made within the scope of the patent application or its equivalent should still fall within the scope of the invention patent.

Claims (13)

A wide-angle imaging lens group includes sequentially from an object side to an image side: a first lens having a negative refractive power, the first lens including an object side and an image side, and the object side of the first lens is A convex surface, the image side of the first lens is concave; an aperture; a second lens having a positive refractive power, the second lens includes an object side and an image side, and the object side of the second lens is convex A third lens having a positive refractive power, the third lens including an object side and an image side, and the image side of the third lens is convex; and a fourth lens having a negative refractive power, the fourth The lens includes an object side and an image side, the object side of the fourth lens is concave, and the image side of the fourth lens is convex; and the wide-angle imaging lens group satisfies the following conditions: 0.5 <| f1 / f2 | <1.2; and 0.1 <| f / f4 | <1.2; where f is the effective focal length of the wide-angle imaging lens group, f1 is the focal length of the first lens, f2 is the focal length of the second lens, and f4 is the first Focal length of four lenses. For example, the wide-angle imaging lens group of the first patent application scope, wherein the thicknesses of the first lens to the fourth lens on the optical axis are CT1, CT2, CT3, and CT4, respectively, and the image side of the first lens The distance from the object side of the second lens to the optical axis is AT1, and the wide-angle imaging lens group satisfies the following conditions: 0.1 <AT1 / (CT1 + CT2 + CT3 + CT4) <0.42. For example, the wide-angle imaging lens group of the first patent application scope, wherein the curvature radii of the object side and the image side of the first lens are R1 and R2, respectively, and the wide-angle imaging lens group satisfies the following conditions: 1 <( R1 + R2) / (R1-R2) <2.7. For example, the wide-view imaging lens group of the first patent application scope, wherein the third lens has a dispersion coefficient of V3, the fourth lens has a dispersion coefficient of V4, and the wide-view imaging lens group satisfies the following conditions: 0.2 <V4 / V3 <0.5. For example, the wide-angle imaging lens group of the first patent application scope, wherein one and a half of the maximum viewing angle of the wide-angle imaging lens group is HFOV, which satisfies the following conditions: 45 degrees <HFOV <85 degrees. For example, the wide-angle imaging lens group of the first patent application scope, wherein the image side of the second lens is convex. For example, the wide-angle imaging lens group of the sixth aspect of the patent application, wherein the image side of the second lens is concave at a distance from the optical axis. For example, the wide-angle imaging lens group of the first patent application scope, wherein the image side of the second lens is concave. For example, the wide-angle imaging lens group of the first patent application scope, wherein the object side of the third lens is convex. For example, the wide-angle imaging lens group of the first patent application scope, wherein the object sides and the image sides of the first lens to the fourth lens are aspheric. For example, the wide-angle imaging lens group in the second scope of the patent application, wherein the wide-angle imaging lens group more satisfies the following conditions: 0.1 <| f / f4 | <1. An imaging device includes a wide-angle imaging lens group as described in the first patent application. An electronic device includes the imaging device according to item 12 of the scope of patent application.