TWI645215B - Five-piece optical lens system with a wide field of view - Google Patents

Abstract

The invention is a five-piece wide-angle lens group comprising: a first lens having a negative refractive power and a glass material; a second lens having a positive refractive power; an aperture; a three lens having a positive refractive power; a fourth lens having a negative refractive power; and a fifth lens having a positive refractive power. Accordingly, the present invention provides a five-piece wide-angle lens group having a wide viewing angle, high resolution, short lens length, and small distortion.

Description

Five-piece wide-angle lens group

The present invention relates to a five-piece wide-angle lens group, and more particularly to a miniaturized five-piece wide-angle lens group for use in electronic products.

With the development of high-profile mobile devices such as smart phones and tablets, high-quality small photographic lenses are standard equipment, and with the popularity of the online community, more and more people like to take pictures or take selfies with others. Sharing, as well as game consoles, driving recorders, security camera lenses, etc., are also increasingly demanding for shooting angles, so the requirements for lens shooting angle and image quality are becoming more and more strict. Conventional US 8335043, US 8576497 use 2 lens groups, 5-6 pieces to achieve a large angle purpose, but its distortion is too large, such as US 8593737, US 8576497, US 8395853, its maximum field of view (FOV) Both are less than 85 degrees, and the total length (TL) of the lens group is also too long.

Secondly, the use of photographic lenses in biomedical, driving recorders, cameras or other electronic products does not require too much aperture requirements, but the need for angles and lens lengths is a problem that the industry needs to address further. At present, the photographic lenses conventionally mounted on the electronic products in the aforementioned fields mainly adopt a four-piece lens structure, and all have defects such as insufficient drawing angle and long lens length.

Therefore, how to develop a wide-angle lens group with wide viewing angle, high resolution capability, short lens length, and small distortion is the motivation for the development of the present invention.

It is an object of the present invention to provide a five-piece wide-angle lens group, and more particularly to a five-piece wide-angle lens group having a wide viewing angle, high resolution, short lens length, and small distortion.

In order to achieve the foregoing object, a five-piece wide-angle lens group according to the present invention includes, in order from the object side to the image side, a first lens having a negative refractive power and a glass material, the object side surface thereof. The near optical axis is a convex surface, and the image side surface is concave at the near optical axis, and at least one surface of the object side surface and the image side surface is aspherical; a second lens has a positive refractive power, and the object side surface is near the optical axis The concave surface is convex on the side surface of the image side surface, and at least one surface of the object side surface and the image side surface is aspherical; an aperture; a third lens having a positive refractive power and a near side optical axis of the object side surface The convex surface is convex, and the image side surface is convex at the near optical axis, and at least one surface of the object side surface and the image side surface is aspherical; a fourth lens has a negative refractive power, and the object side surface is concave at the near optical axis The image side surface has a convex surface at a near optical axis, and at least one surface of the object side surface and the image side surface is aspherical; and a fifth lens having a positive refractive power, the object side surface being convex at a near optical axis, At least one surface of the object side surface and the image side surface is Spherical object-side surface and image-side surface of at least one surface having at least one inflection point.

Preferably, wherein the focal length of the first lens is f1, the focal length of the second lens is f2, and the following condition is satisfied: -1.1 < f1/f2 < -0.25. Thereby, the refractive power arrangement of the first lens and the second lens is suitable, which is advantageous for obtaining a wide angle of view (angle of view) and reducing excessive increase of system aberration.

Preferably, wherein the focal length of the second lens is f2, the focal length of the third lens is f3, and the following condition is satisfied: 2.1 < f2 / f3 < 5. Thereby, the arrangement of the refractive power of the second lens and the third lens is balanced, which contributes to the correction of the aberration and the reduction of the sensitivity.

Preferably, wherein the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the following condition is satisfied: -1.6 < f3 / f4 < -0.7. Thereby, the total optical length of the system is effectively reduced.

Preferably, wherein the focal length of the fourth lens is f4, the focal length of the fifth lens is f5, and the following condition is satisfied: -1 < f4 / f5 < - 0.45. Thereby, the refractive power arrangement of the rear group lens system can be balanced, which is beneficial to the reduction of system sensitivity and the correction of high-order aberrations.

Preferably, wherein the focal length of the first lens is f1, the focal length of the third lens is f3, and the following condition is satisfied: -2.6 < f1/f3 < -1.8. Thereby, the refractive power of the first lens is effectively distributed, and the sensitivity of the five-piece wide-angle lens group is lowered.

Preferably, wherein the focal length of the second lens is f2, the focal length of the fourth lens is f4, and the following condition is satisfied: -5.0 < f2 / f4 < -3.1. Therefore, the system's negative refractive power distribution is more suitable, which is beneficial to correct system aberrations to improve the imaging quality of the system.

Preferably, wherein the focal length of the third lens is f3, the focal length of the fifth lens is f5, and the following condition is satisfied: 0.57 < f3 / f5 < 1.05. Thereby, it contributes to shortening the total length of the five-piece wide-angle lens group and maintaining the miniaturization thereof.

Preferably, wherein the focal length of the first lens is f1, the combined focal length of the second lens and the third lens is f23, and the following condition is satisfied: -3.15<f1/f23<-2.15. Thereby, when f1/f23 satisfies the above conditions, the five-piece wide-angle lens group can be significantly improved in image resolution while obtaining a wide angle of view (angle of view).

Preferably, wherein the combined focal length of the second lens and the third lens is f23, the combined focal length of the fourth lens and the fifth lens is f45, and the following condition is satisfied: -0.35<f23/f45<0.3. When f23/f45 satisfies the foregoing relationship, the five-piece wide-angle lens group can have a large picture angle, a high pixel and a low lens height, and the resolution capability is remarkably improved. Conversely, if the optical data value is exceeded The range will result in problems such as low performance, low resolution, and insufficient yield of the five-piece wide-angle lens group.

Preferably, wherein the combined focal length of the first lens and the second lens is f12, the combined focal length of the third lens and the fourth lens is f34, and the following condition is satisfied: -3.6 < f12 / f34 < - 0.07. Thereby, it is advantageous to obtain a wide angle of view (angle of view) and to effectively correct the curvature of field.

Preferably, wherein the combined focal length of the third lens and the fourth lens is f34, the focal length of the fifth lens is f5, and the following condition is satisfied: -46 < f34 / f5 < 8. When f34/f5 satisfies the foregoing relationship, the five-piece wide-angle lens group can have a large picture angle, a high pixel and a low lens height, and the resolution capability is remarkably improved. Conversely, if the optical data value is exceeded The range will result in problems such as low performance, low resolution, and insufficient yield of the five-piece wide-angle lens group.

Preferably, wherein the focal length of the first lens is f1, the combined focal length of the second lens, the third lens and the fourth lens is f234, and the following condition is satisfied: -1 < f1/f234 < -0.17. By proper configuration of the refractive power, it helps to reduce the occurrence of spherical aberration and astigmatism.

Preferably, wherein the second lens, the third lens and the fourth lens have a combined focal length of f234, the fifth lens has a focal length of f5, and satisfies the following condition: 2<f234/f5<5.5. By proper configuration of the refractive power, it helps to reduce the occurrence of spherical aberration and astigmatism.

Preferably, wherein the first lens, the second lens and the third lens have a combined focal length of f123, the fourth lens has a focal length of f4, and satisfies the following condition: -0.8<f123/f4<-0.3. By proper configuration of the refractive power, it helps to reduce the occurrence of spherical aberration and astigmatism.

Preferably, wherein the first lens, the second lens and the third lens have a combined focal length of f123, the fourth lens and the fifth lens have a combined focal length of f45, and satisfy the following condition: -0.28<f123/f45<0.27 . By proper configuration of the refractive power, it helps to reduce the occurrence of spherical aberration and astigmatism.

Preferably, wherein the focal length of the first lens is f1, the combined focal length of the second lens, the third lens, the fourth lens and the fifth lens is f2345, and the following condition is satisfied: -2.3<f1/f2345<-1.6 . Thereby, when f1/f2345 satisfies the foregoing relationship, the five-piece wide-angle lens group can have a large picture angle. At the same time, the resolution capability is significantly improved. Conversely, if the optical data value range is exceeded, the performance of the five-piece wide-angle lens group, low resolution, and insufficient yield are caused.

Preferably, wherein the first lens has a dispersion coefficient of V1, the second lens has a dispersion coefficient of V2, and satisfies the following condition: 27 < V1 - V2 < 40. Thereby, the chromatic aberration of the five-piece wide-angle lens group is effectively reduced.

Preferably, wherein the third lens has a dispersion coefficient of V3, the fourth lens has a dispersion coefficient of V4, and satisfies the following condition: 27<V3-V4<40. Thereby, the chromatic aberration of the five-piece wide-angle lens group is effectively reduced.

Preferably, wherein the overall focal length of the five-piece wide-angle lens group is f, the distance from the object side surface of the first lens to the imaging plane on the optical axis is TL, and the following condition is satisfied: 0.05 < f / TL < 0.2 . Thereby, it is advantageous to obtain a wide picture angle (angle of view) and to facilitate the miniaturization of the five-piece wide-angle lens group to be mounted on a thin electronic product.

With regard to the techniques, means, and other effects of the present invention in light of the above-described objects, the preferred embodiments are described in detail with reference to the drawings.

100, 200, 300, 400, 500‧ ‧ aperture

110, 210, 310, 410, 510‧‧‧ first lens

111, 211, 311, 411, 511 ‧ ‧ ‧ side surface

112, 212, 312, 412, 512‧‧‧ image side surface

120, 220, 320, 420, 520‧‧‧ second lens

121, 221, 321, 421, 521‧‧‧ ‧ side surface

122, 222, 322, 422, 522‧‧‧ image side surface

130, 230, 330, 430, 530‧‧‧ third lens

131, 231, 331, 431, 531‧‧‧ ‧ side surface

132, 232, 332, 432, 532‧‧‧ image side surface

140, 240, 340, 440, 540 ‧ ‧ fourth lens

141, 241, 341, 441, 541 ‧ ‧ ‧ side surface

142, 242, 342, 442, 542‧‧‧ side surface

150, 250, 350, 450, 550 ‧ ‧ fifth lens

151, 251, 351, 451, 551 ‧ ‧ ‧ side surface

152, 252, 352, 452, 552‧‧‧ side surface

160, 260, 360, 470, 570‧‧‧ Infrared filtering filter elements

170, 270, 370‧ ‧ protective glass

180, 280, 380, 480, 580‧‧ ‧ imaging surface

190, 290, 390, 490, 590‧‧ ‧ optical axis

f‧‧‧Focus of the five-piece imaging lens set

Aperture value of Fno‧‧‧ five-piece imaging lens set

Maximum field of view in the FOV‧‧‧ five-piece imaging lens set

F1‧‧‧The focal length of the first lens

F2‧‧‧The focal length of the second lens

f3‧‧‧The focal length of the third lens

F4‧‧‧The focal length of the fourth lens

f5‧‧‧Focus of the fifth lens

F12‧‧‧Combined focal length of the first lens and the second lens

F23‧‧‧Combined focal length of the second lens and the third lens

F34‧‧‧Combined focal length of the third lens and the fourth lens

F45‧‧‧Combined focal length of the fourth lens and the fifth lens

F123‧‧‧Combined focal length of the first lens, the second lens and the third lens

f234‧‧‧Combined focal length of the second lens, the third lens and the fourth lens

F2345‧‧‧Combined focal length of the second lens, the third lens, the fourth lens and the fifth lens

V2‧‧‧Dispersion coefficient of the second lens

V3‧‧‧Dispersion coefficient of the third lens

V4‧‧‧Dispersion coefficient of the fourth lens

Dispersion coefficient of V5‧‧‧ fifth lens

TL‧‧‧The distance from the object side surface of the first lens to the imaging surface on the optical axis

Fig. 1A is a schematic view showing a five-piece wide-angle lens group according to a first embodiment of the present invention.

Fig. 1B is a graph showing the curvature of field and the distortion of the five-piece wide-angle lens group of the first embodiment from left to right.

2A is a schematic view of a five-piece wide-angle lens group according to a second embodiment of the present invention.

2B is a graph showing the curvature of field and the distortion of the five-piece wide-angle lens group of the second embodiment from left to right.

Fig. 3A is a schematic view showing a five-piece wide-angle lens group of a third embodiment of the present invention.

Fig. 3B is a graph showing the curvature of field and the distortion of the five-piece wide-angle lens group of the third embodiment from left to right.

4A is a schematic view of a five-piece wide-angle lens group according to a fourth embodiment of the present invention.

4B is a graph showing the curvature of field and the distortion of the five-piece wide-angle lens group of the fourth embodiment from left to right.

Fig. 5A is a schematic view showing a five-piece wide-angle lens group according to a fifth embodiment of the present invention.

Fig. 5B is a graph showing the curvature of field and the distortion of the five-piece wide-angle lens group of the fifth embodiment from left to right.

<First Embodiment>

1A and FIG. 1B, FIG. 1A is a schematic diagram of a five-piece wide-angle lens group according to a first embodiment of the present invention, and FIG. 1B is a five-piece wide-angle lens group of the first embodiment from left to right. Image curvature and distortion curve. As can be seen from FIG. 1A, the five-piece wide-angle lens assembly includes an aperture 100 and an optical group. The optical group includes a first lens 110, a second lens 120, a third lens 130, and a fourth from the object side to the image side. The lens 140, the fifth lens 150, the infrared filter element 160, the cover glass 170, and the imaging surface 180, wherein the five-piece wide-angle lens group has five sheets of refractive power. The aperture 100 is disposed between the image side surface 122 of the second lens 120 and the object side surface 131 of the third lens 130.

The first lens 110 has a negative refractive power and is made of glass. The object side surface 111 is convex at the near optical axis 190, and the image side surface 112 is concave at the near optical axis 190, and the object side surface 111 and the image side are Surface 112 is aspherical.

The second lens 120 has a positive refractive power and is made of a plastic material. The object side surface 121 is a concave surface at the near optical axis 190, and the image side surface 122 is convex at the near optical axis 190, and the object side surface 121 and the image side are Surface 122 is aspherical.

The third lens 130 has a positive refractive power and is made of a plastic material. The object side surface 131 is convex at the near optical axis 190, and the image side surface 132 is convex at the near optical axis 190, and the object side surface 131 and the image side are The surfaces 132 are all aspherical.

The fourth lens 140 has a negative refractive power and is made of a plastic material. The object side surface 141 is concave at the near optical axis 190, and the image side surface 142 is convex at the near optical axis 190, and the object side surface 141 and the image side are Surfaces 142 are all aspherical.

The fifth lens 150 has a positive refractive power and is made of a plastic material. The object side surface 151 is convex at the near optical axis 190, and the image side surface 152 is concave at the near optical axis 190, and the object side surface 151 and the image side are The surface 152 is aspherical, and at least one surface of the object side surface 151 and the image side surface 152 has at least one inflection point.

The infrared filter element 160 is made of glass and disposed between the fifth lens 150 and the cover glass 170 without affecting the focal length of the five-piece wide-angle lens group.

The cover glass 170 is made of glass and is disposed between the infrared filter element 160 and the imaging surface 180 without affecting the focal length of the five-piece wide-angle lens group. The cover glass 170 is used to protect the sensing element (not shown).

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

Where z is the position value with reference to the surface apex at a position of height h in the direction of the optical axis 190; c is the curvature of the lens surface near the optical axis 190, and is the reciprocal of the radius of curvature (R) (c = 1/R) R is the radius of curvature of the lens surface near the optical axis 190, h is the vertical distance of the lens surface from the optical axis 190, k is a conic constant, and A, B, C, D, E, G, ... ...is a high-order aspheric coefficient.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the five-piece wide-angle lens group is f, the aperture value (f-number) of the five-piece wide-angle lens group is Fno, and the maximum magnification of the five-piece wide-angle lens group. Field angle (Drawing angle) is FOV, and its value is as follows: f = 1.63 (mm); Fno = 2.0; and FOV = 173 (degrees).

In the five-piece wide-angle lens group of the first embodiment, the focal length of the first lens 110 is f1, the focal length of the second lens 120 is f2, and the following condition is satisfied: f1/f2 = -0.498.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the second lens 120 is f2, the focal length of the third lens 130 is f3, and the following condition is satisfied: f2/f3 = 4.072.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the third lens 130 is f3, the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f3/f4 = -1.019.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the fourth lens 140 is f4, the focal length of the fifth lens 150 is f5, and the following condition is satisfied: f4/f5 = -0.827.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the first lens 110 is f1, the focal length of the third lens 130 is f3, and the following condition is satisfied: f1/f3=-2.026.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the second lens 120 is f2, the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f2/f4=-4.150.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the third lens 130 is f3, the focal length of the fifth lens 150 is f5, and the following condition is satisfied: f3/f5=0.844.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the first lens 110 is f1, the combined focal length of the second lens 120 and the third lens 130 is f23, and the following condition is satisfied: f1/f23=-2.338 .

In the five-piece wide-angle lens group of the first embodiment, the composite focal length of the second lens 120 and the third lens 130 is f23, and the combined focal length of the fourth lens 140 and the fifth lens 150 is f45, and the following conditions are satisfied: F23/f45=0.110.

In the five-piece wide-angle lens group of the first embodiment, the composite focal length of the first lens 110 and the second lens 120 is f12, and the combined focal length of the third lens 130 and the fourth lens 140 is f34, and the following conditions are met: F12/f34=-1.508.

In the five-piece wide-angle lens group of the first embodiment, the combined focal length of the third lens 130 and the fourth lens 140 is f34, and the focal length of the fifth lens 150 is f5, and the following condition is satisfied: f34/f5=7.688.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the first lens is f1, and the combined focal length of the second lens 120, the third lens 130, and the fourth lens 140 is f234, and the following conditions are met: f1/ F234=-0.765.

In the five-piece wide-angle lens group of the first embodiment, the combined focal length of the second lens 120, the third lens 130, and the fourth lens 140 is f234, and the focal length of the fifth lens 150 is f5, and the following condition is satisfied: f234 /f5=2.234.

In the five-piece wide-angle lens group of the first embodiment, the composite focal length of the first lens 110, the second lens 120, and the third lens 130 is f123, and the focal length of the fourth lens 140 is f4, and the following condition is satisfied: f123 /f4=-0.612.

In the five-piece wide-angle lens group of the first embodiment, the composite focal length of the first lens 110, the second lens 120, and the third lens 130 is f123, and the combined focal length of the fourth lens 140 and the fifth lens 150 is f45. And the following conditions are met: f123/f45=0.076.

In the five-piece wide-angle lens group of the first embodiment, the focal length of the first lens 110 is f1, and the combined focal length of the second lens 120, the third lens 130, the fourth lens 140, and the fifth lens 150 is f2345, and The following conditions are met: f1/f2345=-1.849.

In the five-piece wide-angle lens group of the first embodiment, the first lens 110 has a dispersion coefficient of V1, and the second lens 120 has a dispersion coefficient of V2 and satisfies the following condition: V1 - V2 = 33.3.

In the five-piece wide-angle lens group of the first embodiment, the third lens 130 has a dispersion coefficient of V3, and the fourth lens 140 has a dispersion coefficient of V4 and satisfies the following condition: V3-V4=34.6.

In the five-piece wide-angle lens group of the first embodiment, the overall focal length of the five-piece wide-angle lens group is f, and the distance from the object side surface 111 to the imaging surface 180 of the first lens 110 on the optical axis 190 is TL. And the following conditions are met: f / TL = 0.158.

Refer to Table 1 and Table 2 below for reference.

Table 1 is the detailed structural data of the first embodiment of Fig. 1A, in which the unit of curvature radius, thickness and focal length is mm, and the surfaces 0-17 sequentially represent the surface from the object side to the image side. Table 2 is the aspherical data in the first embodiment, wherein the cone coefficients in the a-spherical curve equation of k, A, B, C, D, E, F, ... are high-order aspheric coefficients. In addition, the tables in the following embodiments correspond to the schematic diagrams of the respective embodiments and the curvature of field and the distortion diagram of the distortion, and the definitions of the data in the table are the same as those of Tables 1 and 2 of the first embodiment, and Add a statement.

<Second embodiment>

Please refer to FIG. 2A and FIG. 2B , wherein FIG. 2A is a schematic diagram of a five-piece wide-angle lens group according to a second embodiment of the present invention, and FIG. 2B is a five-piece wide-angle lens group of the second embodiment from left to right. Image curvature and distortion curve. As can be seen from FIG. 2A, the five-piece wide-angle lens assembly includes an aperture 200 and an optical group. The optical group includes a first lens 210, a second lens 220, a third lens 230, and a fourth from the object side to the image side. The lens 240, the fifth lens 250, the infrared filter element 260, the cover glass 270, and the imaging surface 280, wherein the five-piece wide-angle lens group has five sheets of refractive power. The aperture 200 is disposed between the image side surface 222 of the second lens 220 and the object side surface 231 of the third lens 230.

The first lens 210 has a positive refractive power and is made of glass. The object side surface 211 is convex at the near optical axis 290, and the image side surface 212 is concave at the near optical axis 290, and the object side surface 211 and the image side are Surface 212 is aspherical.

The second lens 220 has a negative refractive power and is made of a plastic material. The object side surface 221 is concave at the near optical axis 290, and the image side surface 222 is convex at the near optical axis 290, and the object side surface 221 and the image side are Surfaces 222 are all aspherical.

The third lens 230 has a positive refractive power and is made of a plastic material. The object side surface 231 is convex at the near optical axis 290, and the image side surface 232 is convex at the near optical axis 290, and the object side surface 231 and the image side are Surfaces 232 are all aspherical.

The fourth lens 240 has a negative refractive power and is made of a plastic material. The object side surface 241 is concave at the near optical axis 290, and the image side surface 242 is convex at the near optical axis 290, and the object side surface 241 and the image side are Surface 242 is aspherical.

The fifth lens 250 has a positive refractive power and is made of a plastic material. The object side surface 251 is convex at the near optical axis 290, and the image side surface 252 is concave at the near optical axis 290, and the object side surface 251 and the image side are The surface 252 is aspherical, and at least one surface of the object side surface 251 and the image side surface 252 has at least one inflection point.

The infrared filter element 260 is made of glass and is disposed between the fifth lens 250 and the cover glass 270 without affecting the focal length of the five-piece wide-angle lens group.

The cover glass 270 is made of glass and disposed between the infrared filter element 260 and the imaging surface 280 without affecting the focal length of the five-piece wide-angle lens group. The cover glass 270 is used to protect the sensing element (not shown).

Refer to Table 3 and Table 4 below.

In the second embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

With Table 3 and Table 4, the following data can be derived:

<Third embodiment>

Please refer to FIG. 3A and FIG. 3B , wherein FIG. 3A is a schematic diagram of a five-piece wide-angle lens group according to a third embodiment of the present invention, and FIG. 3B is a five-piece wide-angle lens group of the third embodiment from left to right. Image curvature and distortion curve. As can be seen from FIG. 3A, the five-piece wide-angle lens assembly includes an aperture 300 and an optical group. The optical group includes a first lens 310, a second lens 320, a third lens 330, and a fourth from the object side to the image side. The lens 340, the fifth lens 350, the infrared filter element 360, the cover glass 370, and the imaging surface 380, wherein the five-piece wide-angle lens group has five lenses with refractive power. The aperture 300 is disposed between the image side surface 322 of the second lens 320 and the object side surface 331 of the third lens 330.

The first lens 310 has a positive refractive power and is made of glass. The object side surface 311 is convex at the near optical axis 390, and the image side surface 312 is concave at the near optical axis 390, and the object side surface 311 and the image side are Surfaces 312 are all aspherical.

The second lens 320 has a negative refractive power and is made of a plastic material. The object side surface 321 is concave at the near optical axis 390, and the image side surface 322 is convex at the near optical axis 390, and the object side surface 321 and the image side are Surfaces 322 are all aspherical.

The third lens 330 has a positive refractive power and is made of a plastic material. The object side surface 331 is convex at the near optical axis 390, and the image side surface 332 is convex at the near optical axis 390, and the object side surface 331 and the image side are Surface 332 is aspherical.

The fourth lens 340 has a negative refractive power and is made of a plastic material, and the object side surface 341 is concave at the near optical axis 390, and the image side surface 342 is convex at the near optical axis 390, and the object side surface 341 and the image side are Surfaces 342 are all aspherical.

The fifth lens 350 has a positive refractive power and is made of a plastic material. The object side surface 351 is convex at the near optical axis 390, and the image side surface 352 is concave at the near optical axis 390, and the object side surface 351 and the image side are The surface 352 is aspherical, and at least one surface of the object side surface 351 and the image side surface 352 has at least one inflection point.

The infrared filter element 360 is made of glass and disposed between the fifth lens 350 and the cover glass 370 without affecting the focal length of the five-piece wide-angle lens group.

The cover glass 370 is made of glass and disposed between the infrared filter element 360 and the imaging surface 380 without affecting the focal length of the five-piece wide-angle lens group. The cover glass 370 is used to protect the sensing element (not shown).

Refer to Table 5 and Table 6 below for reference.

In the third embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

With Table 5 and Table 6, the following data can be derived:

<Fourth embodiment>

4A and 4B, wherein FIG. 4A is a schematic diagram of a five-piece imaging lens set according to a fourth embodiment of the present invention, and FIG. 4B is a five-piece imaging lens set of the fourth embodiment from left to right. Image curvature and distortion curve. As can be seen from FIG. 4A, the five-piece imaging lens assembly includes an aperture 400 and an optical group. The optical group includes a first lens 410, a second lens 420, a third lens 430, and a fourth from the object side to the image side. The lens 440, the fifth lens 450, the infrared filter element 470, and the imaging surface 480, wherein the five-piece imaging lens group has five lenses with refractive power. The aperture 400 is disposed between the image side surface 422 of the second lens 420 and the object side surface 431 of the third lens 430.

The first lens 410 has a negative refractive power and is made of glass. The object side surface 411 is convex at the near optical axis 490, and the image side surface 412 is concave at the near optical axis 490, and the object side surface 411 and the image side are Surface 412 is aspherical.

The second lens 420 has a positive refractive power and is made of a plastic material. The object side surface 421 is concave at the near optical axis 490, and the image side surface 422 is convex at the near optical axis 490, and the object side surface 421 and the image side are Surface 422 is aspherical.

The third lens 430 has a positive refractive power and is made of a plastic material. The object side surface 431 is convex at the near optical axis 490, and the image side surface 432 is convex at the near optical axis 490, and the object side surface 431 and the image side are Surface 432 is aspherical.

The fourth lens 440 has a negative refractive power and is made of a plastic material. The object side surface 441 is concave at the near optical axis 490, and the image side surface 442 is convex at the near optical axis 490, and the object side surface 441 and the image side are Surface 442 is aspherical.

The fifth lens 450 has a positive refractive power and is made of a plastic material, and the object side surface 451 is near The optical axis 490 is a convex surface, and the image side surface 452 is convex at the near optical axis 490, and the object side surface 451 and the image side surface 452 are aspherical surfaces, and the object side surface 451 and the image side surface 452 are at least one. The surface has at least one inflection point.

The infrared filter element 470 is made of glass and disposed between the fifth lens 450 and the imaging surface 480 without affecting the focal length of the five-piece imaging lens set.

Refer to Table 7 and Table 8 below for reference.

In the fourth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Table 7 and Table 8:

<Fifth Embodiment>

5A and 5B, wherein FIG. 5A is a schematic diagram of a five-piece imaging lens set according to a fifth embodiment of the present invention, and FIG. 5B is a five-piece imaging lens group of the fifth embodiment from left to right. Image curvature and distortion curve. As can be seen from FIG. 5A, the five-piece imaging lens assembly includes an aperture 500 and an optical group. The optical group includes a first lens 510, a second lens 520, a third lens 530, and a fourth from the object side to the image side. The lens 540, the fifth lens 550, the infrared filter element 570, and the imaging surface 580, wherein the five-piece imaging lens group has five refractive lenses. The aperture 500 is disposed at the The image side surface 522 of the second lens 520 is between the object side surface 531 of the third lens 530.

The first lens 510 has a positive refractive power and is made of glass. The object side surface 511 is convex at the near optical axis 590, and the image side surface 512 is concave at the near optical axis 590, and the object side surface 511 and the image side are Surface 512 is aspherical.

The second lens 520 has a negative refractive power and is made of a plastic material. The object side surface 521 is concave at the near optical axis 590, and the image side surface 522 is convex at the near optical axis 590, and the object side surface 521 and the image side are Surface 522 is aspherical.

The third lens 530 has a positive refractive power and is made of a plastic material. The object side surface 531 is convex at the near optical axis 590, and the image side surface 532 is convex at the near optical axis 590, and the object side surface 531 and the image side are Surface 532 is aspherical.

The fourth lens 540 has a negative refractive power and is made of a plastic material. The object side surface 541 is concave at the near optical axis 590, and the image side surface 542 is convex at the near optical axis 590, and the object side surface 541 and the image side are Surface 542 is aspherical.

The fifth lens 550 has a positive refractive power and is made of a plastic material. The object side surface 551 is convex at the near optical axis 590, and the image side surface 552 is convex at the near optical axis 590, and the object side surface 551 and the image side are The surface 552 is aspherical, and the object side surface 551 and the image side surface 552 have at least one surface having at least one inflection point.

The infrared filter element 570 is made of glass and disposed between the fifth lens 550 and the imaging surface 580 without affecting the focal length of the five-piece wide-angle lens group.

Refer to Table 9 and Table 10 below.

In the fifth embodiment, the aspherical curve equation represents the form as in the first embodiment. In addition, the definitions of the parameters in the following table are the same as those in the first embodiment, and are not described herein.

The following data can be derived from Table 9 and Table 10:

The five-piece wide-angle lens group provided by the invention can be made of plastic or glass. When the lens material is plastic, the production cost can be effectively reduced. When the lens is made of glass, the five-piece wide-angle lens group can be increased. The freedom of force configuration. In addition, the object side surface and the image side surface of the lens in the five-piece wide-angle lens group may be aspherical, and the aspheric surface can be easily formed into a shape other than the spherical surface, and more control variables are obtained to reduce the aberration and thereby reduce the lens. The number used, and thus the total length of the five-piece wide-angle lens group of the present invention can be effectively reduced.

In the five-piece wide-angle lens group provided by the present invention, in the case of a lens having a refractive power, if the surface of the lens is convex and the position of the convex surface is not defined, it indicates that the surface of the lens is convex at the near optical axis; When the lens surface is concave and the concave position is not defined, it indicates that the lens surface is concave at the near optical axis.

The five-piece wide-angle lens group provided by the invention is more suitable for the optical system of moving focus, and has the characteristics of excellent aberration correction and good imaging quality, and can be applied to 3D (three-dimensional) image capturing and digital in many aspects. In electronic imaging systems such as cameras, mobile devices, digital tablets or car photography.

In the above, the above embodiments and drawings are only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equivalent changes and modifications made by the scope of the present invention are all It should be within the scope of the patent of the present invention.

Claims (19)

A five-piece wide-angle lens group comprising, in order from the object side to the image side, a first lens having a negative refractive power and being made of glass, the object side surface being convex at the near optical axis, and the image side surface being near the optical axis a concave surface, at least one surface of the object side surface and the image side surface is aspherical; a second lens having a positive refractive power, the object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis At least one surface of the object side surface and the image side surface is aspherical; an aperture; a third lens having a positive refractive power, the object side surface being convex at the near optical axis, and the image side surface being convex at the near optical axis At least one surface of the object side surface and the image side surface is aspherical; a fourth lens has a negative refractive power, and the object side surface is concave at the near optical axis, and the image side surface is convex at the near optical axis, At least one surface of the side surface and the image side surface is aspherical; and a fifth lens having a positive refractive power, the object side surface being convex at a near optical axis, and at least one surface of the object side surface and the image side surface being aspherical, The object side surface and the image side surface have at least one surface At least one inflection point; wherein the focal length of the fourth lens element is f4, the focal length of the fifth lens is f5, and the following relationship is satisfied: -1 <f4 / f5 ≦ -0.790. The five-piece wide-angle lens group according to claim 1, wherein the focal length of the first lens is f1, the focal length of the second lens is f2, and the following condition is satisfied: -1.1 < f1/f2 < -0.25. The five-piece wide-angle lens group according to claim 1, wherein the focal length of the second lens is f2, the focal length of the third lens is f3, and the following condition is satisfied: 2.1 < f2 / f3 < 5. The five-piece wide-angle lens group according to claim 1, wherein the focal length of the third lens is f3, the focal length of the fourth lens is f4, and the following condition is satisfied: -1.6 < f3 / f4 < -0.7. The five-piece wide-angle lens group according to claim 1, wherein the focal length of the first lens is f1, the focal length of the third lens is f3, and the following condition is satisfied: -2.6 < f1/f3 < -1.8. The five-piece wide-angle lens group according to claim 1, wherein the focal length of the second lens is f2, the focal length of the fourth lens is f4, and the following condition is satisfied: -5.0 < f2 / f4 < -3.1. The five-piece wide-angle lens group according to claim 1, wherein the focal length of the third lens is f3, the focal length of the fifth lens is f5, and the following condition is satisfied: 0.57 < f3 / f5 < 1.05. The five-piece wide-angle lens group according to claim 1, wherein a focal length of the first lens is f1, a combined focal length of the second lens and the third lens is f23, and the following condition is satisfied: - 3.15 < f1/f23 < -2.15. The five-piece wide-angle lens group according to claim 1, wherein the combined focal length of the second lens and the third lens is f23, and the combined focal length of the fourth lens and the fifth lens is f45, and the following condition is satisfied: -0.35 <f23/f45<0.3. The five-piece wide-angle lens group according to claim 1, wherein a combined focal length of the first lens and the second lens is f12, and a combined focal length of the third lens and the fourth lens is f34, and the following condition is satisfied: -3.6 <f12/f34<-0.07. The five-piece wide-angle lens group according to claim 1, wherein a combined focal length of the third lens and the fourth lens is f34, and a focal length of the fifth lens is f5, and the following condition is satisfied: -46<f34/f5< 8. The five-piece wide-angle lens group according to claim 1, wherein a focal length of the first lens is f1, and a combined focal length of the second lens, the third lens, and the fourth lens is f234, and the following condition is satisfied: -1< F1/f234<-0.17. The five-piece wide-angle lens group according to claim 1, wherein a composite focal length of the second lens, the third lens, and the fourth lens is f234, and a focal length of the fifth lens is f5, and the following condition is satisfied: 2<f234 /f5<5.5. The five-piece wide-angle lens group according to claim 1, wherein the first lens, the second lens and the third lens have a combined focal length of f123, the fourth lens has a focal length of f4, and satisfies the following condition: -0.8< F123/f4<-0.3. The five-piece wide-angle lens group according to claim 1, wherein the first lens, the second lens and the third lens have a combined focal length of f123, and the fourth lens and the fifth lens have a combined focal length of f45, and satisfy the following Conditions: -0.28 < f123 / f45 < 0.27. The five-piece wide-angle lens group according to claim 1, wherein a focal length of the first lens is f1, and a combined focal length of the second lens, the third lens, the fourth lens, and the fifth lens is f2345, and the following conditions are satisfied. :-2.3<f1/f2345<-1.6. The five-piece wide-angle lens group according to claim 1, wherein the first lens has a dispersion coefficient of V1, the second lens has a dispersion coefficient of V2, and satisfies the following condition: 27 < V1 - V2 < 40. The five-piece wide-angle lens group according to claim 1, wherein the third lens has a dispersion coefficient of V3, the fourth lens has a dispersion coefficient of V4, and satisfies the following condition: 27<V3-V4<40. The five-piece wide-angle lens group according to claim 1, wherein the overall focal length of the five-piece wide-angle lens group is f, and the distance from the object side surface of the first lens to the imaging surface on the optical axis is TL, and satisfies The following conditions were: 0.05 < f / TL < 0.2.