TWM530408U - Five-piece large aperture wide-angle lens - Google Patents

Description

Five-piece large aperture wide-angle lens

This creation is about an optical lens, especially for a five-piece lens with miniaturization, large aperture, and wide-angle characteristics.

In response to the popularity of camera modules equipped with mobile devices, thinner and high-resolution camera modules have become the goal pursued by various manufacturers. In order to maintain thinning and high-pixel features, photosensitive elements need to shrink pixels in a limited area. Achieving high pixel demand, but small pixels have the disadvantage of poor photosensitive performance, it is necessary to increase the aperture to make up; in addition, the previous mobile device camera module is only functional considerations, the lens group consists of only 3 to 4 lenses Nowadays, in pursuit of performance, the photosensitive element is tens of thousands of pixels, so the lens group needs to include more than 4 lenses to meet the demand, but the 6 lenses can not effectively reduce the volume.

In view of this, the main purpose of the present invention is to provide a miniaturized lens having a large aperture characteristic, which is not only small in size, but also has high optical performance and high luminous flux characteristics, and can maintain good chromatic aberration.

In order to achieve the above object, the present invention provides a five-piece large aperture wide-angle lens, which includes a first lens, a second lens, a third lens, a fourth lens, and an order along an optical axis from the object side to the image side. a fifth lens, in addition to an aperture; the first lens has a positive refractive power, the radius of curvature of the object side is R1, the radius of curvature of the image side surface is R2, wherein R1>0; the second lens has a negative refractive power, and the curvature of the object side The radius is R3, the radius of curvature of the image side is R4, where R3>R4>0; the third lens has positive refractive power, the radius of curvature of the object side is R5, and the radius of curvature of the image side surface is R6, where R5>0; the fourth mirror The sheet has a positive refractive power, the radius of curvature of the object side is R7, and the radius of curvature of the image side surface is R8, wherein R7 < R8 < 0; the optical axis region of the fifth lens has a negative refractive power, and the surrounding region has a positive refractive power, and the optical axis region is The surrounding area is bounded by a line connecting the inflection point, wherein the radius of curvature of the object side surface is R9, and the radius of curvature of the image side surface is R10, wherein R9<0<R10; the aperture is located on the object side of the first lens Or between the first and second lenses; and the lens more satisfies the conditional formula of 2.5<R7/R8<6.

With the above design, the lens of the present invention can be combined with miniaturization, large aperture, and wide-angle characteristics.

1‧‧‧Five-piece large aperture wide-angle lens

10‧‧‧ first lens

20‧‧‧second lens

30‧‧‧ third lens

40‧‧‧Fourth lens

50‧‧‧ fifth lens

52‧‧‧ Optical axis area

54‧‧‧ surrounding area

56‧‧‧reflex point connection

60‧‧‧ flat lenses

70‧‧‧Photosensitive elements

L‧‧‧ optical axis

A‧‧‧ object side

B‧‧‧ image side

ST‧‧‧ aperture

1 is a schematic view of a first embodiment of the present creation; FIG. 1A is a lateral chromatic aberration diagram of the first embodiment of the creation; FIG. 1B is an axial chromatic aberration diagram of the first embodiment of the creation; The distortion diagram of the first embodiment; the second diagram is a schematic view of the second embodiment of the creation; the second diagram is the lateral chromatic aberration diagram of the second embodiment of the creation; and the second diagram B is the axial chromatic aberration of the second embodiment of the creation Fig. 2C is a distortion diagram of the second embodiment of the creation; Fig. 3 is a schematic view of the third embodiment of the creation; Fig. 3A is a lateral chromatic aberration diagram of the third embodiment of the creation; The axial chromatic aberration diagram of the third embodiment; FIG. 3C is a distortion diagram of the third embodiment of the creation.

Please refer to FIG. 1 , which is a first embodiment of the present invention. The five-piece large aperture wide-angle lens 1 sequentially includes a first lens 10 and an image lens A on the optical axis L from the object side A to the image side B. Aperture ST, a second lens 20, a third lens 30, a fourth lens 40, and a fifth lens 50, the five lenses 10, 20, 30, 40, 50 are lens combinations with refractive power A CCD, CMOS or other photosensitive element 70 is disposed on the image side B, and a flat lens 60 such as a filter and/or a cover glass may be disposed between the photosensitive element 70 and the fifth lens 50. The quantity can be increased or decreased or not set according to demand.

"Positive refractive power (or negative refractive power)" as used in this specification means that the refractive power of the optical axis calculated by Gaussian optical theory is positive (or negative). The area near the optical axis is the optical axis area, and the area around the optical axis area is the surrounding area. The optical axis area and the surrounding area are bounded by a line of inflection point, and the line connecting the inflection point refers to the lens path. In addition, the partial lens further includes an extension portion located on an outer circumference of the surrounding area for assembling the lens in a lens, and the ideal imaging light does not pass through the extension portion. In addition, the shape of the optical axis region can be judged according to the general knowledge in the field, and the R value (referring to the radius of curvature of the paraxial axis, generally referred to as the R value on the lens data in the optical software) positive and negative judgment bump . In the aspect of the object, when the R value is positive, it is judged to be convex, when the R value is negative, it is judged as concave; on the image side, when R is positive, it is judged as concave, when R is negative When it is judged to be convex.

In this embodiment, the first lens 10 has a positive refractive power, and the curvature radius R1 of the object side surface is 1.691, and the curvature radius R2 of the image side surface is -15.235. The object side surface of the first lens 10 is a convex surface, and the image of the first lens 10 is The side surface is convex, the first lens 10 provides the five-piece large aperture wide-angle lens 1 main refractive power; in other possible embodiments, R1 may have other changes, but R1 must be greater than 0 (R1>0), in addition, R2 except It can be less than 0 or greater than 0 (R2<0 or R2>0).

The aperture ST is located between the first and second lenses 10, 20 to balance the manufacturing convenience with the amount of incident light.

The second lens 20 has a negative refractive power, and the object side curvature radius R3 is 4.113, the image side curvature radius R4 is 1.469, the object side surface of the second lens 20 is a convex surface, and the image side surface of the second lens 20 is a concave surface. The chromatic dispersion coefficient of the second lens 20 is less than 30, which can effectively reduce the chromatic aberration problem that is likely to occur in the wide-angle lens. In other possible embodiments, R3 and R4 may have other changes, but R3 must be greater than R4, and R4 must be greater than 0 (R3>R4 >0).

The third lens 30 has a positive refractive power, and the object side curvature radius R5 is 5.952, the image side curvature radius R6 is -10.470, the object side surface of the third lens 30 is a convex surface, and the image side surface of the third lens 30 is a convex surface. The third lens 30 can increase the amount of light entering to achieve a large aperture. In other possible embodiments, R5 can have other changes, but R5 must be greater than 0 (R5>0). In addition, R6 can be greater than 0. 0 (R6<0 or R6>0).

The fourth lens 40 has a positive refractive power, and the object side curvature radius R7 is -2.998, the image side curvature radius R8 is -1.022, the R7/R8 is 2.934, and the object side of the fourth lens 40 is concave. The fourth lens 40 The image side of the image is convex, and the fourth lens 40 can effectively correct astigmatism and curvature of field, can maintain the high light input amount while shortening the full length of the lens and maintain image quality; in other possible embodiments, R7 and R8 can have other changes. However, R7 must be less than R8, and R8 must be less than 0 (R7<R8<0), and must satisfy the conditional formula of 2.5<R7/R8<6. If the conditional condition of 2.8<R7/R8<5.7 is satisfied, the above The second condition allows for a shorter lens length and maintains good chromatic aberration.

The fifth lens 50 has an optical axis region 52 at the center, and a peripheral region 54 is formed around the optical axis region 52. The optical axis region 52 has a negative refractive power, and the peripheral region 54 has a positive refractive power, and the optical axis region 52 and the periphery. The area 54 is bounded by an inflection point line 56, and the side of the optical axis area 52 is curved. The rate radius R9 is -3.000, and the image side curvature radius R10 is 1.558. The fifth lens 50 can effectively correct the aberration caused by the large aperture, and the positive refractive power can shorten the total length of the lens. In other possible embodiments, R9 and R10 can There are other changes, except that R9 must be less than 0 and R10 must be greater than 0 (R9<0<R10).

The design parameters of the five-piece large aperture wide-angle lens 1 of the first embodiment are as shown in Table 1 below:

Wherein, 0.657 mm in the distance column refers to the distance between the vertex of the side surface 1 of the first lens object and the vertex of the image side surface 2, 0.004 mm refers to the distance between the image side surface 2 and the aperture ST, and 0.028 mm means the aperture ST and the first The distance between the apex of the side 3 of the second lens 10, and the like; the radius of curvature refers to the radius of curvature at the intersection of the optical axis and the side of the object or the side of the image. In the first embodiment, the first to fifth lenses 10, 20, 30 The object side and the image side of 40, 50 are aspherical, and the surface shape thereof satisfies the following formula:

Where z is the aspherical depth (ie the point on the aspherical surface from the optical axis h, the vertical optical axis and the aspherical vertex, the distance between the two), c = 1 / r, r is the surface radius of curvature , h is the distance between the point on the aspheric surface and the optical axis, k is the cone coefficient, A is the fourth order coefficient, B is the sixth order coefficient, C is the eighth order coefficient, D is the tenth order coefficient, E is The twelfth order coefficient, F is the fourteenth order coefficient, and G is the fifteenth order coefficient. The parameters of each aspheric surface of the first embodiment are as shown in Table 2 below:

Based on the foregoing design, the system focal length value f of the five-piece large aperture wide-angle lens 1 of the present embodiment is 3.6 mm, the system length TTL (Total Track Length) is 4.48 mm, and the field of view of the maximum image height (FOV, Field Of View) ) up to 76.6 degrees, the aperture value (f-number) is up to 2.

Wherein, the ratio of the focal length value f (3.6 mm) of the system to the distance D23 (0.241 mm) of the second and third lenses 20, 30 on the optical axis is 14.94, and the focal length value f (3.6 mm) of the system is the first The ratio of the distance D12 (0.032 mm) of the second lens 10, 20 on the optical axis is 112.50, and the ratio of the focal length f3 (6.99 mm) of the third lens 30 to the focal length f4 (2.59 mm) of the fourth lens 40 is absolutely value 2.70; the ratio of the radius of curvature R1~R10 of each lens to the focal length value f of the system is as shown in Table 3; thus, the five-piece large aperture wide-angle lens 1 can have a large viewing angle and maintain transverse chromatic aberration (transverse chromatic aberration) The maximum color difference is less than 1.5 μm, and the maximum amount of focus of the axial chromatic aberration is about 8.1 μm, and the chromatic aberration is good. The lateral chromatic aberration diagram is shown in Fig. 1A, and the axial chromatic aberration diagram is shown. As shown in Fig. 1B, and more effectively correcting the distortion problem that is likely to occur at a large viewing angle, such as the distortion map shown in Fig. 1C, the maximum distortion variable does not exceed 1.2%.

Please refer to FIG. 2 , which is a second embodiment of the present invention. The lens configuration is similar to that of the first embodiment, except that the aperture ST is located on the object side of the first lens 10 , and the second embodiment provides The design parameters of the five-piece large aperture wide-angle lens 1 are shown in Table 4 below, where R7/R8 is 3.975:

In the second embodiment, the side surfaces and the image side surfaces of the first to fifth lenses 10, 20, 30, 40, 50 are aspherical surfaces, and the surface shape thereof satisfies the following formula, and the definitions of the parameters are as follows:

The parameters of each aspheric surface of the second embodiment are as shown in Table 5 below:

Based on the foregoing design, the focal length f of the system of the present embodiment is 3.53 mm, the system length TTL is 3.93 mm, the angle of view at the maximum image height is 78.4 degrees, and the aperture value (f-number) is 2.

Among them, f/D23 is 12.74, f/D12 is 75.11, For 3.59, the ratio of the radius of curvature R1~R10 of each lens to the focal length value f of the system is shown in Table 6 below. For the lateral chromatic aberration diagram shown in Fig. 2A, the maximum color difference of the lateral chromatic aberration does not exceed 1.6 μm. Referring to the axial chromatic aberration diagram shown in Fig. 2B, the maximum amount of focus of the axial chromatic aberration is about 33 μm. Referring to the distortion diagram shown in Fig. 2C, the maximum distortion is not more than 0.9%.

Please refer to FIG. 3 , which is a third embodiment of the present invention. The lens configuration is similar to that of the first embodiment, except that the aperture ST is located on the object side of the first lens 10 , and the third embodiment provides The design parameters of the five-piece large aperture wide-angle lens 1 are shown in Table 7 below, where R7/R8 is 5.559:

In the third embodiment, the object side surface and the image side surface of the first to fifth lenses 10, 20, 30, 40, 50 are aspherical surfaces, and the surface shape thereof satisfies the following formula:

The parameters of each aspheric surface of the third embodiment are as shown in Table 8 below:

Based on the foregoing design, the focal length f of the system of the present embodiment is 3.32 mm, the system length TTL is 3.73 mm, the angle of view at the maximum image height is 80.7 degrees, and the aperture value (f-number) is 2.2.

Among them, f/D23 is 11.10, f/D12 is 80.98, 2.36, the ratio of the radius of curvature R1~R10 of each lens to the focal length value f of the system is shown in Table IX. Referring to the lateral chromatic aberration diagram shown in Fig. 3A, the maximum color difference of the lateral chromatic aberration does not exceed 1.7 μm. Referring to the axial chromatic aberration diagram shown in Fig. 3B, the maximum amount of focus of the axial chromatic aberration is about 15 μm. Refer to the distortion diagram shown in Fig. 3C, and the maximum distortion is less than 1.1%.

The foregoing three embodiments are only examples of the present invention. Based on the spirit of the present creation, the parameters of the five-piece large aperture wide-angle lens 1 can be changed, for example, the radius of curvature R1 R10 of each lens and the focal length value of the system f. The ratio can be as follows: R1/f is 0.401~0.470, R2/f is -153.326~1.827, R3/f is 1.118~1.256, R4/f is 0.408~0.544, R5/f is 1.653~3.240, R6/f is -5.509~-2.528, R7/f is -2.655~-0.833, R8/f is -0.477~-0.284, R9/f is -1.056~-0.471, R10/f is 0.433~ 1.019; the ratio of the focal length value f of the system to the distance D23 of the second and third lenses 20, 30 on the optical axis may have other changes, so as to satisfy the conditional expression of 10<f/D23<15.5, if 11< The conditional expression of f/D23<15 is better; the ratio of the focal length value f of the system to the distance D12 of the first and second lenses 10, 20 on the optical axis may also have other changes to satisfy the condition of f/D12>45. Preferably, the ratio of the focal length f3 of the third lens 30 to the focal length f4 of the fourth lens 40 is absolute. It is preferably less than 8, so that a shorter optical total length can be obtained and a large aperture is maintained.

The above is only the description of the present embodiment, and may not be used to limit the scope of the patent of this creation. Any simple structural retouching or change that has not been removed from the spirit of this creation should still fall within the scope covered by the patent application scope of this creation.

1‧‧‧Five-piece large aperture wide-angle lens

10‧‧‧ first lens

20‧‧‧second lens

30‧‧‧ third lens

40‧‧‧Fourth lens

50‧‧‧ fifth lens

52‧‧‧ Optical axis area

54‧‧‧ surrounding area

56‧‧‧reflex point connection

60‧‧‧ flat lenses

70‧‧‧Photosensitive elements

L‧‧‧ optical axis

A‧‧‧ object side

B‧‧‧ image side

ST‧‧‧ aperture

Claims (15)

A five-piece large aperture wide-angle lens includes, in order from the object side to the image side along an optical axis: a first lens having a positive refractive power, a radius of curvature of the object side surface being R1, and a radius of curvature of the image side surface being R2, wherein R1>0 a second lens having a negative refractive power, a radius of curvature of the object side surface is R3, a radius of curvature of the image side surface is R4, wherein R3>R4>0; a third lens having a positive refractive power, and a radius of curvature of the object side surface is R5, like The radius of curvature of the side is R6, where R5>0; a fourth lens has a positive refractive power, the radius of curvature of the object side is R7, the radius of curvature of the image side is R8, where R7<R8<0; a fifth lens, the optical axis thereof The area has a negative refractive power, and the surrounding area has a positive refractive power. The optical axis area and the surrounding area are bounded by a line connecting the inflection point. The radius of curvature of the object side surface of the optical axis area is R9, and the radius of curvature of the image side surface is R10. R9<0<R10; and an aperture located between the object side of the first lens or the first and second lenses; and satisfying the conditional expression of 2.5<R7/R8<6. The five-piece large aperture wide-angle lens as described in claim 1 satisfies the conditional formula of 2.8<R7/R8<5.7. The five-piece large aperture wide-angle lens according to claim 1 satisfies the conditional formula of 10<f/D23<15.5, where f is the system focal length value of the five-piece large aperture wide-angle lens, and D23 is the second and third lenses. The distance on the optical axis. The five-piece large aperture wide-angle lens as described in claim 3 satisfies the conditional expression of 11<f/D23<15. The five-piece large aperture wide-angle lens according to any one of claims 1 to 4, which satisfies the conditional expression of f/D12>45, wherein f is a system focal length value of the five-piece large aperture wide-angle lens, and D12 is the first The distance between the first and second lenses on the optical axis. The five-piece large aperture wide-angle lens as described in claim 5 satisfies the following conditional formula: <8, where f3 is the focal length of the third lens, and f4 is the focal length of the fourth lens. The five-piece large aperture wide-angle lens according to claim 1, wherein R1/f is 0.401 to 0.470, and R2/f is -153.326 to 1.827, wherein f is a system focal length value of the five-piece large aperture wide-angle lens. The five-piece large aperture wide-angle lens according to claim 1, wherein R3/f is 1.118~1.256, and R4/f is 0.408~0.544, wherein f is a system focal length value of the five-piece large aperture wide-angle lens. The five-piece large aperture wide-angle lens according to claim 1, wherein R5/f is 1.653~3.240, and R6/f is -5.509~-2.528, wherein f is a system focal length value of the five-piece large aperture wide-angle lens. The five-piece large aperture wide-angle lens according to claim 1, wherein R7/f is -2.655 to -0.833, and R8/f is -0.477 to -0.284, wherein f is a system focal length value of the five-piece large aperture wide-angle lens. The five-piece large aperture wide-angle lens according to claim 1, wherein R9/f is -1.056~-0.471, and R10/f is 0.433~1.019, wherein f is a system focal length value of the five-piece large aperture wide-angle lens. A five-piece large aperture wide-angle lens as claimed in claim 1, wherein R2>0. A five-piece large aperture wide-angle lens as claimed in claim 1, wherein R2 < 0. A five-piece large aperture wide-angle lens as claimed in claim 1, wherein R6>0. A five-piece large aperture wide-angle lens as claimed in claim 1, wherein R6 < 0.