TWI407182B - Wide-angle imaging lens module - Google Patents

Abstract

A wide-angle imaging lens module includes a fixed aperture stop, a first lens, a second lens, a third lens and a fourth lens sequentially disposed between an object and an image. The first lens is a positive lens, and the first lens has a convex surface disposed toward the object and at least one aspheric surface. The second lens has positive refractive power, a concave surface disposed toward the object and at least one aspheric surface. The third lens has positive refractive power, a concave surface disposed toward the object and at least one aspheric surface. The fourth lens has negative refractive power, a convex surface disposed toward the object near the axis and at least one aspheric surface. As such, resolving power and image quality are increased.

Description

Wide-angle imaging lens set

The invention relates to the field of optical lenses, in particular to a four-piece wide-angle imaging lens set having a large picture angle and a large aperture.

With the advancement of technology, 3C products combined with optical lenses have been quite extensive. The user pays more attention to the performance of the optical lens on the 3C product. Not only does the image quality have a high image quality that is close to the camera, but it also hopes to have a wide angle with a large field of view and a low light source. The large aperture performance, especially the driving recorder that has been deeply loved by consumers in recent years, is more focused on the visual field of the optical lens and the recognition effect at night. For this reason, many optical lens factories are racking their brains and want to break through the current predicament to develop An optical lens that combines wide-angle and large aperture characteristics.

However, as of today, the imaging lens designed by the optical lens factory for this kind of products, due to the matching and structural design of the entire lens group, can not meet the design of the large painting angle and the large aperture at the same time, or can slightly enhance the partial angle of the painting. And the aperture, but can not meet the thinning loading requirements of the 3C carrier, and still need to meet the requirements of high imaging quality under the conditions of large painting angle and large aperture. For this reason, the inventor has worked hard for many years to develop and develop a high angle of painting. A wide-angle lens set with an optical lens with large aperture characteristics and enhanced nighttime imaging quality with sufficient amount of light.

One of the objects of the present invention is to provide a wide range of large painting angles and large apertures. Angle imaging lens set.

The second object of the present invention is to provide a wide-angle imaging lens set which is capable of both thinning and high imaging quality while achieving a large angle of drawing and a large aperture.

To achieve the above object, the present invention provides a wide-angle imaging lens set comprising first, second, third, and fourth lenses arranged in an order from an object side to an image side: the first lens having positive refractive power The lens is convex toward the object side; at least one of the surfaces is aspherical; the light barrier; the second lens has a positive refractive power lens and is concave toward the object side; and at least one of the surfaces is aspherical; the third lens a positive refractive lens having a concave surface toward the object side; and at least one of the surfaces is aspherical; the fourth lens has a negative refractive power lens and is convex toward the object side near the optical axis; and at least one of the surfaces is aspherical .

Thereby, the first lens image side and the second lens object side exhibit a symmetrical concave arc surface design, which can satisfy the purpose of large painting angle and large aperture, and the first lens design with large painting angle can provide sufficient The amount of light entering to enhance the high image quality of the optical lens.

The present invention has been described with respect to the preferred embodiments and illustrated by the drawings, wherein the numerical changes of the various embodiments of the present invention are designed, even if other The use of different values for products having the same structure should still fall within the scope of protection of the present invention.

Referring to FIG. 1 and FIG. 2, the wide-angle imaging lens set shown in the second embodiment includes a light column and an optical group, and the optical group includes first, second, third, and fourth lenses L1, L2, and L3. L4 is arranged in the order from the object side A to the image side B: a first lens L1, a diaphragm 1, a second lens L2, a third lens L3, and a fourth lens L4.

The first lens L1 has a positive refractive power lens and is convex toward the object side, and at least one side thereof is aspherical; the second lens L2 has a positive refractive power lens and is concave toward the object side, and at least one side thereof is aspherical; The third lens L3 has a positive refractive power lens which is concave toward the object side, and at least one of which is aspherical; the fourth lens L4 has a negative refractive power lens and is convex toward the object side near the optical axis, and has at least One side is aspherical.

The system of the present invention is a wide-angle imaging lens set composed of four lenses, and a first flat plate glass 2 is disposed behind the fourth lens L4, and the first flat plate glass 2 has the function of filtering infrared rays; A second flat plate glass 3 is added to the front side of the image side B. The second flat plate glass 3 can protect the photosensitive element. The first and second flat plate glasses 2 and 3 are adapted to the image sense of different package structures. The detector can be flexibly increased or decreased to achieve better image quality. In addition, the photosensitive element disposed on the image side B can also be selected according to actual needs of CCD or CMOS.

The wide-angle imaging lens set of the present invention is characterized in that the lens is formed of a plastic material, thereby reducing the cost of material use and management, and also using plastic materials. The lens can be rendered in an aspherical structure with better aberrations, and the aspherical lens design can be used to achieve a higher resolution and thus reduce the number of lenses required for imaging, thereby achieving a thinning effect.

In addition, the difference graph of the present invention is shown in FIG. 1A and FIG. 2A by the non-point difference, the distortion, and the spherical aberration. Regardless of the difference map, the data of the d line is used instead of the point difference. It is about the data of S image (SAGITTAL) and the data of TANGENTIAL, and it is shown in the figure; and it is clear from the difference diagram that the compensation of the invention is the result of the complete simulation design. There is no problem in use.

Referring to FIG. 1B and FIG. 2B of the present invention, the aspherical data of the second embodiment of the present invention, the uppermost data is the code of each lens of the optical group of the present invention: F. No.: the F value is in optical design , representing the brightness parameter, wherein the smaller the F value, the higher the brightness; the angle of view: 2ω; the focus distance f: f is the combined focus distance (mm) of the optical group.

The lower 2, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, and 14 are the number of lens surface numbers in the order of the object side; the number 2 and 3 are the first lens L1. On both sides, the number 5, 6 is the two sides of the second lens L2, the surface numbers 7, 8 are the two sides of the third lens L3, and 9, 10 are the two sides of the fourth lens L4, 11, 12 and 13 14 is the two sides of the first flat plate glass 2 and the second flat plate glass 3, respectively.

In order to achieve the best image quality, the present invention is preferably satisfied by the present invention. Lower condition: First, the focal length value of the first lens L1 and the second lens 12 must be controlled: 3.0<|f1|/|f2|<8.0; wherein f1 is the focal length value of the first lens, and f2 is the focal length value of the second lens .

Then, the focal length value between the second and third lenses must be controlled to match the focal length values of the first and second lenses: 0.05<|f2|/|f3|<2; wherein f2 is the focal length of the second lens , f3 is the focal length value of the third lens.

Furthermore, it is also necessary to control the focal length value of the third lens and the focal length value of the fourth lens: 0.6<|f3|/|f4|<2.1, where f3 is the focal length value of the third lens, and f4 is the focal length value of the fourth lens. .

In addition, in order to achieve high quality imaging, it is necessary to control its refractive index: N4>1.57, V4<40; wherein N4 is the refractive index of the fourth lens, and V4 is the Abbe number of the fourth lens.

In addition, in order to achieve high-quality imaging, it is necessary to control the distance between a first face of the first lens and the image side, the first face being toward the object side; 0.2<|f/TL|<0.7; TL is the distance from the first side of the first lens to the imaging surface, and f is the focal length value of the entire lens group.

If the above optical mode is satisfied, the resolution capability of the wide-angle imaging lens group can be significantly improved. Conversely, if it is smaller or larger than the above numerical range, it will result in Wide-angle imaging lens set performance, low resolution, and insufficient yield.

In addition, each lens of the optical group of the present invention may have an aspherical shape on at least one side, and the aspherical surface shape needs to satisfy the following formula:

Where z is the position value with reference to the surface apex at the height h position along the optical axis; k is the cone constant metric; c is the reciprocal of the radius of curvature; A, B, C, D, E, G,... ...is a high-order aspheric coefficient.

In summary, the present invention utilizes the special design of the first lens L1 as the convex side, the image side as the concave surface, and the second lens L2 on the object side as the concave symmetry concave curved surface, so that the entire optical lens group can be used. The field of view covers the angle of 臻 to 87° to obtain the characteristics of the large painting angle. At the same time, the large angle of the first lens design can also make the aperture reach the bright and large aperture of F2.4, and with a large angle of painting and a large aperture. Provides more sufficient light input, so that the optical lens can obtain better recognition effect and image quality when used at night, and the use of sufficient light source environment can improve the imaging quality of the optical lens by high light input amount.

Furthermore, the first to fourth lenses are all aspherical, which has a significant improvement in the chromatic aberration and aberration of the optical lens, and because the four lenses are aspherical, the wide-angle imaging lens set of the present invention is At the same time, the advantages of large angle of painting and large aperture can be greatly reduced, and the number of lenses can be greatly reduced to meet the demand for thinning of carrier loading. Therefore, the novel first and second lens symmetrical concave arc surface design of the present invention can be obtained. The effect of obviousness is in line with the relevant provisions of the Patent Law. The application for a patent for invention was filed in accordance with the law, and it was considered to be a matter of convenience.

A‧‧‧ object side

B‧‧‧ image side

1‧‧‧ ray

2‧‧‧ first flat glass

3‧‧‧Second flat glass

L1‧‧‧ first lens

L2‧‧‧ second lens

L3‧‧‧ third lens

L4‧‧‧ fourth lens

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a view showing the composition of a lens of a first embodiment of the present invention

Fig. 1A is a diagram showing the difference of the first embodiment of the present invention.

1B is a schematic diagram of optical characteristic data and aspherical coefficient data according to a first embodiment of the present invention.

Figure 2 is a view showing the composition of a lens according to a second embodiment of the present invention.

2A is a diagram showing the difference of the second embodiment of the present invention.

2B is a schematic diagram of optical characteristic data and aspherical coefficient data according to a second embodiment of the present invention.

A‧‧‧ object side

B‧‧‧ image side

1‧‧‧ ray

2‧‧‧ first flat plate glass

L1‧‧‧ first lens

L2‧‧‧ second lens

L3‧‧‧ third lens

L4‧‧‧ fourth lens

Claims (9)

A wide-angle imaging lens set includes a light column and an optical group, and the optical group includes first, second, third, and fourth lenses arranged in an order from the object side to the image side: the first lens, Having a positive refractive power lens and having a convex surface toward the object side; and at least one of the surfaces is aspherical; the light barrier; the second lens having a positive refractive power lens and having a concave surface toward the object side; and at least one of the surfaces being aspherical; a third lens having a positive refractive power lens having a concave surface toward the object side; and at least one of the surfaces having an aspherical surface; the fourth lens having a negative refractive power lens and having a convex surface toward the object side near the optical axis; and at least one side thereof An aspherical surface; the light barrier is disposed between the first lens and the second lens; the wide-angle imaging lens set satisfies the following condition: 3.0<|f1|/|f2|<8.0; wherein f1 is the first The focal length value of the lens, f2 is the focal length value of the second lens. The wide-angle imaging lens set according to claim 1 satisfies the following condition: 0.05<|f2|/|f3|<2; wherein f2 is a focal length value of the second lens, and f3 is a focal length value of the third lens. The wide-angle imaging lens set according to claim 1 satisfies the following condition: 0.05<|f2|/|f3|<2; Where f2 is the focal length value of the second lens, and f3 is the focal length value of the third lens. The wide-angle imaging lens set according to claim 1 satisfies the following condition: 0.6<|f3|/|f4|<2.1; wherein f3 is a focal length value of the third lens, and f4 is a focal length value of the fourth lens. The wide-angle imaging lens set according to claim 3, which satisfies the following condition: 0.6<|f3|/|f4|<2.1; wherein f3 is a focal length value of the third lens, and f4 is a focal length value of the fourth lens. The wide-angle imaging lens set according to claim 1 satisfies the following condition: N4>1.57, V4<40; wherein N4 is the refractive index of the fourth lens, and V4 is the Abbe number of the fourth lens. . The wide-angle imaging lens set according to claim 5, which satisfies the following condition: N4>1.57, V4<40; wherein N4 is the refractive index of the fourth lens, and V4 is the Abbe number of the fourth lens. . The wide-angle imaging lens set according to claim 1 satisfies the following condition: 0.2<|f/TL|<0.7; wherein TL is the distance between a first face of the first lens and the image side, and f is the whole The focal length value of the lens group, the first face being oriented toward the object side. The wide-angle imaging lens set according to claim 7 satisfies the following condition: 0.2<|f/TL|<0.7; wherein TL is the distance between a first face of the first lens and the image side, and f is a whole The focal length value of the lens group, the first face being oriented toward the object side.