ULTRA WIDE-ANGLE LARGE APERTURE LENS

Abstract

An ultra wide-angle large-aperture lens sequentially comprises at least three parts from an object side to an image side: a first lens group G1, a second lens group G2, and a third lens group G3; when an object moves closer from infinity, the first lens group G1 is fixed, the second lens group G2 and the third lens group G3 move, to implement an ultra wide-angle microlens which is in focus and meets the following conditional expressions: 1.2(|F12|+S)/LB2.5(1); 0.8(|F12|+S)/(tan LB)1.3(2).

Claims

1. An ultra wide-angle large-aperture lens, comprising: at least three parts sequentially from an object side to an image side: a first lens group G1 having a negative diopter, a second lens group G2 having a positive diopter or a negative diopter, and a third lens group G3 having a positive diopter, wherein when an object moves closer from infinity, the first lens group G1 is fixed, the second lens group G2 and the third lens group G3 move, to implement an ultra wide-angle microlens which is in focus and meets the following conditional expressions:
1.2(|F12|+S)/LB2.5 (1)
0.8(|F12|+S)/(tan LB)1.3 (2) wherein, F12: a focal length after the first lens group G1 and the second lens group G2 are synthesized in an infinity state; S: a distance from a front-most end surface from the object side of the first lens group to a diaphragm in the infinity state; LB: a distance from a surface, which is closest to an image, to the image in the infinity state; and : a half angle of view of an optical system.

2. The ultra wide-angle large-aperture lens according to claim 1, wherein a conditional expression (3) is met;
0.2(D23+|F12|)(tan LB)0.6 (3) wherein, D23: an interval between the second lens group and the third lens group in the infinity state.

3. The ultra wide-angle large-aperture lens according to e claim 1, wherein a conditional expression (4) is met;
0.5F1/|F12|2 (4) wherein, F1: a focal length of a plus lens in the first lens group.

4. The ultra wide-angle large-aperture lens according to claim 1, wherein a surface, which is closest to the image, of the first lens group G1 is an aspheric surface.

5. The ultra wide-angle large-aperture lens according to claim 4, wherein a shape of the aspheric surface meets conditional expressions (5) and (6):
1.8G2R/SG103 (5)
5G2R/SG510 (6) wherein, G2R: a paraxial radius of curvature of a surface, which is closest to the image side, of the first lens group; SG5: an arc height of the surface, which is closest to the image, of the first lens group when a distance from the center of an optical axis to an effective aperture is equal to half of the radius of curvature, namely G2R/2; and SG10: an arc height of the surface, which is closest to the image, of the first lens group when the distance from the center of an optical axis to an effective aperture is equal to the radius of curvature G2R.

6. The ultra wide-angle large-aperture lens according to claim 1, wherein a full angle of view is over 110 degrees.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is a structural schematic view of Example 1 of the Invention;

[0032] FIG. 2 is a schematic view of aberrations and chromatic difference of Example 1 of the Invention;

[0033] FIG. 3 is a structural schematic view of Example 2 of the Invention;

[0034] FIG. 4 is a schematic view of aberrations and chromatic difference of Example 2 of the Invention;

[0035] FIG. 5 is a structural schematic view of Example 3 of the Invention;

[0036] FIG. 6 is a schematic view of aberrations and chromatic difference of Example 3 of the Invention; and

[0037] FIG. 7 is a schematic view of an arc height of a surface, which is closest to an image side, of a first lens group, and a radius of curvature.

DETAILED DESCRIPTION OF THE INVENTION

[0038] To make the technical measures, new creation features, and achieved objectives and effects of the Invention easy to understand, the following further illustrates the Invention with reference to specific drawings.

EXAMPLE 1

[0039] As shown in FIG. 1, an ultra wide-angle lens of Example 1 sequentially includes, from an object side, a first lens group G1 having a negative diopter, a second lens group G2 having a negative diopter, and a third lens group G3 having a positive diopter.

[0040] A spherical aberration, a field curvature aberration, a distortion aberration, and a chromatic difference of magnification at the maximum image magnification in an infinity state of Example 1 are as shown in FIG. 2. [0041] Data of Example 1 is as follows: [0042] R(mm): a radius of curvature of each surface [0043] D(mm): an interval between lenses and lens thickness [0044] Nd: a refractive index of each glass of line d [0045] Vd: the Abbe number of glass [0046] Focal length: 14.45 [0047] Fno: 2.87 [0048] Half angle of view : 56.5

TABLE-US-00001 Radius of Interval Refractive Abbe Surface curvature R thickness D index Nd number Vd 1 36.5362 1.8000 1.74916 54.67 2 16.8329 4.3538 3 .star-solid. 22.2802 2.0000 1.80610 40.73 4 .star-solid. 13.1551 (variable) 5 21.8600 1.5000 1.92286 20.88 6 13.3977 4.8148 7 38.3679 2.2645 1.71736 29.50 8 85.9242 2.1034 9 31.0409 1.2000 1.49700 81.61 10 18.8780 8.0000 1.65293 36.96 11 55.7546 (variable) 12 Diaphragm inf 2.1500 13 25.9270 3.2856 1.62004 36.30 14 39.1219 6.2990 1.80420 46.50 15 16.3944 2.7253 1.84666 23.78 16 44.2831 0.4489 17 19.9599 1.0000 1.90366 33.00 18 12.0341 8.1020 1.49700 81.61 19 12.0341 1.0000 1.83481 42.72 20 52.1667 0.1500 21 44.2942 6.8895 1.49700 81.61 22 18.6742 0.1500 23 258.9417 1.0000 1.84400 37.34 24 16.5272 8.5741 1.58313 59.46 25 .star-solid. 39.1425 (LB variable)

[0049] Aspheric Surface

TABLE-US-00002 K 4(B) 6(C) 8(D) 10(E) 12(F) 3 0.0433 3.85146e005 2.74884e007 4.22706e010 5.42847e013 1.03343e015 4 0.4853 1.54141e005 3.80388e007 1.97332e009 1.06864e011 1.69260e014 25 0.3308 1.89790e005 9.88484e009 1.92025e010 1.17296e012 3.14002e015

[0050] Definitions of shapes of the aspheric surface:

[0051] y: a radial coordinate starting from an optical axis.

[0052] z: an offset amount, starting from an intersection between the aspheric surface and the optical axis, in the direction of an optical axis.

[0053] r: a radius of curvature of a reference sphere of the aspheric surface.

[0054] K: aspheric coefficients of the 4.sup.th, 6.sup.th, 8.sup.th, 10.sup.th, and 12.sup.th powers.

[00001]$z=\frac{\left(1/r\right).Math.y^2}{1+\sqrt{1-\left(1+K\right).Math.{\left(y/r\right)}^2}}+A.Math..Math.4.Math..Math.y^4+A.Math..Math.6.Math..Math.y^6+A.Math..Math.8.Math..Math.y^8+A.Math..Math.10.Math..Math.y^{10}+A.Math..Math.12.Math..Math.y^{12}$

TABLE-US-00003 Focal length 14.4513 0.025 times D(4) 5.0702 5.5392 D(11) 5.4011 3.9097 LB 38.8100 39.8324

EXAMPLE 2

[0055] As shown in FIG. 3, an ultra wide-angle lens of Example 2 sequentially includes, from an object side, a first lens group G1 having a negative diopter, a second lens group G2 having a negative diopter, and a third lens group G3 having a positive diopter. A spherical aberration, a field curvature aberration, a distortion aberration, and a chromatic difference of magnification at the maximum image magnification in an infinity state of Example 2 are as shown in FIG. 4. [0056] Data of Example 2 is as follows: [0057] R(mm): a radius of curvature of each surface [0058] D(mm): an interval between lenses and lens thickness [0059] Nd: a refractive index of each glass of line d [0060] Vd: the Abbe number of glass [0061] Focal length: 12.5 [0062] Fno: 2.87 [0063] Half angle of view : 60.1

TABLE-US-00004 Radius of Interval Refractive Abbe Surface curvature R thickness D index Nd number Vd 1 41.3919 2.5000 1.74916 54.67 2 23.5576 5.0658 3 .star-solid. 51.6496 2.5000 1.58313 59.46 4 .star-solid. 16.7988 (variable) 5 39.7839 1.5000 1.49700 81.61 6 10.4818 5.1866 7 0.0000 5.5315 1.62588 35.74 8 13.8133 1.0000 1.83481 44.72 9 70.3450 0.2000 10 32.3483 4.8664 1.76182 26.61 11 14.1918 3.0000 1.92286 20.88 12 37.8109 (variable) 13 diaphragm inf 2.6149 14 24.8151 3.3000 1.61293 36.96 15 43.5495 1.2000 1.91082 35.25 16 12.4551 4.5000 1.62004 36.30 17 33.5744 0.1500 18 59.4780 4.2676 1.78472 25.72 19 10.6778 1.0000 1.90366 29.31 20 83.4618 0.1500 21 34.0377 6.6000 1.49700 81.61 22 19.9445 0.1500 23 77.2021 1.0000 1.91082 35.25 24 19.2911 8.7000 1.49700 81.61 25 19.2911 0.5000 26 .star-solid. 15.8048 1.7000 1.80781 40.97 27 .star-solid. 23.9742 (LB variable)

[0064] Aspheric Surface

TABLE-US-00005 K 4(B) 6(C) 8(D) 10(E) 12(F) 3 0.0080 5.00208e005 1.48696e007 2.85395e010 3.26206e013 5.77197e017 4 0.5807 2.41854e005 1.14397e008 1.61462e009 4.64271e012 4.16529e015 26 0.4154 1.60608e004 3.90127e007 1.97932e009 1.00952e011 5.34069e014 27 11.4671 3.56937e005 3.58224e007 4.31857e009 2.03624e011 3.90187e014

[0065] Definitions of shapes of the aspheric surface: [0066] y: a radial coordinate starting from an optical axis. [0067] z: an offset amount, starting from an intersection between the aspheric surface and the optical axis, in the direction of an optical axis. [0068] r: a radius of curvature of a reference sphere of the aspheric surface. [0069] K: aspheric coefficients of the 4.sup.th, 6.sup.th, 8.sup.th, 10.sup.th, and 12.sup.th powers.

[00002]$z=\frac{\left(1/r\right).Math.y^2}{1+\sqrt{1-\left(1+K\right).Math.{\left(y/r\right)}^2}}+A.Math..Math.4.Math..Math.y^4+A.Math..Math.6.Math..Math.y^6+A.Math..Math.8.Math..Math.y^8+A.Math..Math.10.Math..Math.y^{10}+A.Math..Math.12.Math..Math.y^{12}$

TABLE-US-00006 Focal length 12.500 0.02 times D(4) 10.1074 10.1118 D(12) 5.1500 4.6207 LB 38.8325 39.3529

EXAMPLE 3

[0070] As shown in FIG. 5, an ultra wide-angle lens of Example 3 sequentially includes, from an object side, a first lens group G1 having a negative diopter, a second lens group G2 having a positive diopter, and a third lens group G3 having a positive diopter, a spherical aberration, a field curvature aberration, a distortion aberration, and a chromatic difference of magnification at the maximum image magnification in an infinity state of Example 3 are as shown in FIG. 6. [0071] Data of Example 3 is as follows: [0072] R(mm): a radius of curvature of each surface [0073] D(mm): an interval between lenses and lens thickness [0074] Nd: a refractive index of each glass of line d [0075] Vd: the Abbe number of glass [0076] Focal length: 12.34 [0077] Fno: 2.87 [0078] Half angle of view : 65.3

TABLE-US-00007 Radius of Interval Refractive Abbe Surface curvature R thickness D index Nd number Vd 1 49.1688 3.0000 1.88300 40.80 2 28.7369 5.9510 3 .star-solid. 38.3771 3.0000 1.76222 39.10 4 .star-solid. 13.2216 (variable) 5 .star-solid. 26.3504 2.0000 1.80610 40.73 6 .star-solid. 21.9484 1.0000 7 29.0498 1.2000 1.92286 20.88 8 15.7852 6.0387 9 155.4907 1.2000 1.49700 81.61 10 17.3034 14.0589 1.60460 34.14 11 30.1628 (variable) 12 Diaphragm inf 0.3000 13 51.0241 0.8000 1.88300 40.80 14 16.2177 4.8578 1.61685 32.93 15 22.3133 0.3000 16 26.5661 0.8000 1.88300 40.80 17 15.3661 3.6600 1.92286 20.88 18 60.4796 0.3000 19 21.2781 0.8000 1.91082 35.25 20 14.2411 8.9962 1.49700 81.61 21 14.2411 0.8000 1.91082 35.25 22 31.0060 0.3000 23 45.1155 7.3580 1.49700 81.61 24 23.5371 0.3000 25 208.2211 0.8000 1.90366 31.31 26 16.9897 10.9515 1.58037 66.66 27 .star-solid. 33.0129 (LB variable)

[0079] Aspheric Surface

TABLE-US-00008 K 4(B) 6(C) 8(D) 10(E) 12(F) 3 0.0000 1.08543e005 6.58994e008 1.76009e010 2.50521e013 1.39500e016 4 1.1525 5.06484e006 9.76877e008 8.42213e012 3.75716e013 3.58386e016 5 6.9451 2.98647e005 8.67891e008 7.99109e011 4.26182e013 7.25791e016 6 1.0036 5.24665e005 2.72339e007 1.42729e009 6.56722e012 2.77682e014 27 0.0000 1.02224e005 5.86171e009 4.23996e011 4.86295e014 5.96462e016

[0080] Definitions of shapes of the aspheric surface:

[0081] y: a radial coordinate starting from an optical axis.

[0082] z: an offset amount, starting from an intersection between the aspheric surface and the optical axis, in the direction of an optical axis.

[0083] r: a radius of curvature of a reference sphere of the aspheric surface.

[0084] K: aspheric coefficients of the 4.sup.th, 6.sup.th, 8.sup.th, 10.sup.th, and 12.sup.th powers.

[00003]$z=\frac{\left(1/r\right).Math.y^2}{1+\sqrt{1-\left(1+K\right).Math.{\left(y/r\right)}^2}}+A.Math..Math.4.Math..Math.y^4+A.Math..Math.6.Math..Math.y^6+A.Math..Math.8.Math..Math.y^8+A.Math..Math.10.Math..Math.y^{10}+A.Math..Math.12.Math..Math.y^{12}$

TABLE-US-00009 Focal length 10.3417 0.02 times D(4) 10.0602 10.2346 D(11) 11.8296 11.4532 LB 38.6008 38.8027

[0085] Summary Table of Conditional Expressions

TABLE-US-00010 Exam- Exam- Exam- ple 1 ple 2 ple 3 Conditional expression (1): 1.480 1.661 2.334 1.2 (|F12| + S)/LB 2.5 Conditional expression (2): 0.980 0.955 1.073 0.8 (|F12| + S)/(tan LB) 1.3 Conditional expression (3): 0.452 0.380 0.511 0.2 (D23 + |F12|)/(tan LB) 0.6 Conditional expression (4): 1.077 1.499 0.645 0.5 F1/|F12| 2 Conditional expression (5): 2.317 2.187 2.296 1.8 G2R/SG10 3 Conditional expression(6): 7.767 7.466 8.164 5 G2R/SG5 10

[0086] Basic principles and main features of the Invention as well as advantages of the Invention are shown and described above. Those skilled in the art should understand that the Invention is not limited to the foregoing Examples. The above Examples and the description in the specification are merely used for illustrating the principle of the Invention, and the Invention may further have various changes and improvements without departing from the spirit and scope of the Invention. All these changes and improvements fall in the protection scope of the Invention. The protection scope of the Invention is defined by the appended claims and equivalencies thereof.